Just not sure I buy that she's been Hungry every time her eyes are described as grey, especially when they're described as getting silvery when she is shown to be getting Hungry.

I theorize that Lara cultivates a lowkey Hunger continuously; that she *intentionally* under-Feeds, and if she ever really indulges, then she avoids going out in public for a day or two, until her Hunger begins to stir again.

Being Hungry makes her sharper, more-alert, more-dangerous.
Being Hungry makes her sexier, more physical, more powerful.
 

We know that Mab rode with the Conqueror, but we don't know if she was already Mab ...

Just so.
Now, what I'm wondering is:  which "Conqueror"?
Honestly:  I think most of the fans presume William of Normandy; I myself am much less sure.

For one thing: this snippet comes from Ethniu, who despises mortals!  I don't think she'd adopt so fanciful (and basically respectful) a title to describe any mortal whatsoever.
 

... We don't know if Titania has been replaced.

We do, though -- Mab & Titania were born twins.  Presumably they became fae around the same time, with a pair of Ladymantles.

We have "over a thousand years" that Mab has been Mab (i.e. Queen of Winter) and I suspect, particular, it was about 1330 years ago (roughly Arthurian era) -- because that's 2x the 666year Starborn/Outsider cycles (rounded down to the nearest decade).  Those big Outsider-Wars are hard on the Fae.  Or maybe go for 3 of those cycles, and we're back to the time of Yeshua son of Mary ...

We don't know how long Mab & Titania were Ladies, though.  Immortals, they could have lasted a long time!
Even the names aren't great clues -- "Mab" is Celtic(Brythonic) in origin, "Titania" is Latin, first recorded in Ovid.
Maybe a Celt/Roman couple who had twins, and named one for each background?

But in any case, the Queens have been replaced much more than the Mothers have;
and the Ladies more-often still;
and the Knights get used up like a box of Kleenex during cold-season.

  I don't think it has to have, I think the mantle on it's own accord would go to the nearest available vessel.

Doubtful.
Demonreach is all about capturing Powers.  If Harry were to genuinely target Mab, her Mantle would be captured (stripped of  her Mantle, Mab is likely a broken mortal shell).

  I remember reading a comment that Jim made about at some point Harry is really going to be pissed at Lea ...

IIRC, Jim said "if Harry knew what she had done..."

I don't know if Jim intends to have a Big Reveal moment for this (where Harry finds out); or if it's going to be one of those "backgrounder" elements (like the Oblivion War) that Harry's never going to learn about.  Or if Jim himself hasn't yet decided (this is where I think Jim is (or was when he spoke at the time)).

I agree though, that Lea killing Malcolm would qualify; and it's... not an unlikely scenario!

But also:  I think Harry's POV might be that Lea "killed" Maggie Sr. by withdrawing the "Cannot find/target magically" protection from her, in the moment Harry was born.  I mean, it probably happened more or less automatically -- Lea didn't "pull the trigger" -- but it doubtless happened with Lea's full awareness & consent... she could have extended the coverage/protection (at least for a little while).  I just don't think Harry has connected those dots, yet (and may never).

... somehow I can't see Harry ever being resigned to that and that would blow up Mab's plans big time. So I don't think that happened ...

And yet Harry can & does work with entities he hates.
He worked repeatedly with Marcone.  He worked with Lea, despite distrusting her; and with Mab, back when he considered her the "archetypal queen of wickedness, who could teach a lesson to all the other villains."  He literally followed Nicodemus to Hell, in SG.  What Lea (presumably) did to Maggie, and/or Malcolm, may be unforgivable.  But it won't necessarily be the end of everything.

... Unless, Nemesis was already manipulating Lea to some degree.  We know her desire for power even before she got the Knife in Grave Peril ...

WoJ says Mab chose Lea as her Handmaiden way-back-when because Lea would be the challenge Mab needed to stay on her toes, to sharpen herself against.  I think Lea's ambition was simply the pathway Nemesis found, to entice/seduce Lea.

... My theory is that Lea and Mab encouraged and talked Margaret into taking up with Lord Raith.  Why?  Because Mab wanted to know, needed to know what was behind the White Court's power, what was the Hunger all about? ...

The Whampire Court has been a thing for the entirety of Mab's tenure as Queen of Winter, and her information-gathering abilities are extraordinary.  I think she already knew the nature of the Hungers.

I think Mab put Maggie into Raith's path *specifically* in conjunction with the "starbabe" plan.  I think Mab's "get a Starborn Winterknight" goes all the way back that far, to years before Harry's birth!

... she wanted to see for herself just how well her star born Knight would do up against it... 

This, I agree with.  Harry's whole "Hero's Journey" growth-path includes a major component of him powering-up to be able to face the BAT; it was a "test" but also another training-exercise, building up his ability to handle that sort of foe on a sustained basis (not just a brawl but a negotiation); as Mother Winter says, it is among the least of them... but as Mab points out, it's still one of them (and while Harry needs to grow fast, he needs to not be broken in the process, by facing too-tough a challenge too-soon).

...  But back to Margaret, what Mab hadn't planned was for Margaret to have a child by Raith.  I am unsure at this point how Thomas fits into Mab's long term plans and goals, he has complicated them a bit, but not sure if she can use him to her advantage one way or the other.  I think Mab got lucky when Margaret met and fell in love with Malcolm, simply because that motivated Margaret to leave Raith.  I believe Margaret as Raith's lover had not only found out just what the Hunger Demon was, ( Mab's plan to begin with) but she gained enough information to know that while she herself couldn't kill it, she knew how to stop it from feeding and deprive Raith in her death curse of much of if not all of his power. 

Margaret knew very well what a star born was, and that being one gave a star born power over Outsiders.  She also knew that the known star born, or at least the ones introduced in the series as known star born aside from Harry, have serious flaws.  As in being power hungry and brutal among other things.  This is where Malcolm comes in, repeated over and over again along with Harry's strong will is the fact that he inherited his father's good heart or nature.  This, if Lash is to believed, gave her the idea that with Malcolm as sire, Margaret could not only give birth to a star born child, but one that could lead the fight against the Outsiders. Mab encouraged this line of thinking, then Margaret proceeded to bargain for Harry to have a real Fae godmother, i.e. Lea.  However I think both parties were holding back in the bargaining process, Margaret never told Mab that Malcolm understood and agreed to conceive this child.  That Margaret reasoned that this star born child would be different from those that came before him.  Mab held back from Margaret her plans on just how she would use this child to her advantage and manipulate him... 

I go much further back for Mab's plans:  she knows the whole Starborn/Apocalypse cycle.  She wanted a Starborn Winterknight, this time around; perhaps her WK last cycle failed in the face of Outsiders?  So she looked around... and found Margaret, already rebellious & a "Wayward" daughter (pun absolutely intended!).  Nice strong magic talent, great for passing along to her kids.  Perfect stock to breed a Winterknight!  I doubt that was Mab's only such plan; I more than halfway-expect that Elaine Mallory was another such (but "balance" called for Summer to get Elaine, as Winter was getting Harry).

I think it was Mab -- acting through Handmaiden Lea -- who carefully hinted to Maggie Sr. about the coming Apocalypse, about the Starborn/Outsider cycle, and what a Starborn was & could be; enough to plant seeds of curiosity, coyly refusing to say more, to reveal expensive/potent secrets.  Maggie could do a bunch of her own research, fill in her own details; she thought the "starbabe" plan was her own... but it was the plan seeded by Mab.  It was the plan Maggie was trying to get the Blackstaff onboard with, that fateful night when Ariana saw the two of them "arguing like family."

I'm unclear why (& how!) exactly Maggie left Raith Père (but I think she left her "starbabe" plan behind when she left Raith).  I presume the Awesome Vampire Sex was still being Awesome.  We saw in 12M that Lara got Harry to the point where she *could* have broken his will, if she had wanted (also note how much the WC & Eb & early/mid Ramirez worried about Harry being brainbent by Whamps -- Whampire control of wizards is clearly a "credible threat").  Maybe Raith (at that point, still much stronger than Lara!) was coming close to breaking Maggie's will, and she realized & bailed-out?  Maybe she realized that giving Raith&Co access to a Starbabe was a  Really Bad Idea^(TM)?   Maybe it was Lea:  she's the Faerie demigoddess of Muses/Inspiration, maybe she "inspired" Maggie to flee (Faerie power on the Leanansidhe's scale is one of the things likely to be able to overcome a Whampire-addiction; and Mab's power was likely available as backup if needed).  Maybe it was "all of the above, plus more."  I presume Mab or Lea to be part of Maggie's escape, simply because we haven't seen anything (other than Morgan's "untrackable" favor from Titania) that could have kept Raith's Entropy-Curse spells from targeting Maggie & (sooner or later) killing her.

Enter Malcolm, Stage Left.  A truly Good Man (KotC-level Good, though not a Knight).  This was Uriel's play (obviously), but given the Mab/Uriel shenanigans we have seen, I don't doubt Mr. Sunshine was more than marginally aware of what Mab had simmering in her cauldron!  But after swimming for a decade in the shark-infested waters with Whampires & Rampires & we-don't-know-what-else, I imagine Margaret LaFey's soulgaze with Malcolm was a life-changing experience (and I expect Uriel had a damned good idea what that impact would feel like to her).  But falling in love with him, her old hopes to Change the World for the Better flared up again:  perhaps a starbabe born & raised by such a Good Man could after all become the force-for-Good in the world that she originally had hoped for?  Also maybe a healthy dollop of old-fashioned "in love, want to have children together;" but she had to at least have been willing for Harry to be a Starborn:  she knew the "starbabe how-to" (and thus how-not-to) & could easily have prevented it ... if she had wanted to insure she wouldn't put that destiny onto her&Malcolm's child.

... A huge reason as to why Mab has only been partly successful in her manipulation, is that part of Harry's nature that he inherited from his father.  Mab didn't exactly get the star born Knight she thought she wanted, she has actually gotten the one she needed.  Over time since Harry has become her Knight, I think she is beginning to see that.

I don't think she has seen that, no.  She recognizes that she's got a stronger, better knight than any she's had in a long time; and (since he is the reaping of her decades-old sowing) she thinks she understands why he's so much better; but she's wrong.

I think it's Harry's rearing with Malcolm that makes the difference, not an "inherited" trait.  Aristotle (or maybe the Jesuits; it depends who you ask) famously said, "Give me a child until he is seven and I will show you the man."  Malcolm raised Harry for those first few formative years.  I don't think Mab understands in the slightest what that really means; to the extent she (thinks she) knows, she considers it "softness" and "weakness" and she is trying to purge it from Harry. But it's too much a part of who and what he is.

Much more than her harsh methods, Harry's strength is based upon love itself, learned from Malcolm.

... The relationship between Lara and Harry is merely the next phase or step in Mab's plans leading up to the coming battle. Stay tuned..

Oh, I'm 100% onboard with this!  Everything at this point is Mab's work preparing for the upcoming Apocalypse (or defending herself, so as to minimize the cost, so she's more-ready for the battle).

No, there was a point to it, she was making a point, she could control him.  It wasn't pain, for pain's sake, Mab was teaching Harry an important lesson, she had his contract, she could make him do stuff which he argued she couldn't.  So Mab forced him to impale his hand on the letter spike.   Mab believes pain can be a good teacher, one that Harry believed, one that he believed so well, that he was willing to kill himself because he feared by becoming her Knight he was becoming her complete puppet.
No, it wasn't out of spite, she had a point to make, and she made it.
No, it was a teachable moment, as Mab would say, Harry didn't believe she had his contract with Lea, nor did he believe she could make him do what she wanted. Not exactly true if we are to believe Uriel's seven words, but Mab only had to deceive.  She wasn't lying because she could and can make Harry do anything she wants him to do.. However it was also a deception or bit of a lie, because while she can force him to do just about anything, she can't change him if he doesn't want to be changed.  Harry understands that now, he didn't when he agreed to become her Knight. 

You are remembering a different moment.
You describe correctly the one where she "proves to him" that she has his contract, by forcing him to stab himself.

Later -- as she's departing -- she hurts him, directly.
It's that moment she says, she did it out of spite.

I agree. If I understand correctly, human identity changes much than, for example, Mab's identity (Uriel would be an even more extreme example).  In fact, I am wondering if perhaps the Names that Chauncy got for Harry are not so usefur right now.

I suspect that they are:  Harry I think expects so, for one thing.

But also:  everyone who has Soulgazed Harry is still immune to further Soulgaze with him; and Jim has said that someone *can* reset that, and be Soulgazed anew, if they change sufficiently.

My suspicion is that both changes are changes to the Soul -- the core identity.
I doubt we will get clarity unless somebody asks for a WoJ during an AMA event.