To each their own. The list of questions for Jim grows and sadly I don't think he will answer any of them soon.
Kemmler was associated with the Thule Society though in Fistful of Warlocks, I believe. He also did have a cadre of apprentices and allies - demons, vampires, some of the nastier Fae. He was hardly alone. We've even met at least three of them (Cowl, Grevane, and the Corpsetaker) if not more potentially (two unnamed apprentices in A Fistful of Warlocks) and possibly even others yet to be revealed. I can't say for certain he started the Black Council. But he did much of what they were doing while he was alive. He was destabilising the world order, he was upsetting the balances of power, and he particularly went after the White Council - just like the Black Council. He also used the same symbol as the Denarians (the anarchy pentagram) in a Fistful of Warlocks - and considering it seems like Thorned Namshiel built that particular circle in Small Favor, and he was/is one of the likeliest Black Council candidates on the Denarians prior to Marcone bonding with him, it seems like a link.
Kemmler didn't mind underlings, but he doesn't seem like a team player. I don't get the sense that the Black Council is as old as Kemmler, but they could have been inspired by him.
Again, she was hardly the first person to do that. Kemmler did it, DuMorne did it. Likely other dark wizards. The single biggest indication is that she was fighting to make the Laws fairer and that she was plotting to do just that with dubious persons.
I mean, DuMorne did it as part of the Black Council and after Maggie Sr, presumably. Does he really count as another example?
Also, we don't know Simon is Cowl. We don't know if Maggie and Simon ever met. It's possible but not confirmed, and Cowl's identity is also not confirmed. We do know that Simon and Maggie were associated, possibly even friends/lovers. But it's harder to make any guesses without more of Maggie's history.
Do we know that Maggie Sr and Simon were associated independently? The implication ran the other direction on my part. Assume Simon=Cowl (supported by the Eb relationship circumstances and how few if any named characters fit better) then Maggie Sr. as BC founder would be aware of seemingly the BC's leader.
It's interesting, because on the one hand we can assume with reasonable certainty that the Outsiders precede Creation. Therefore Nemesis is as old as anything. On the other hand, several characters have referred to Nemesis as "a new force". I think it's likely that Nemesis has been bound or dormant prior to the events of the series but someone unleashed it. Maybe Maggie, maybe Kemmler, maybe Justin, who knows?
Who has referred to Nemesis as "new"? The BC is a new force, but I don't think BC=Nemesis.
Maggie would have had to be absolutely nuts to think that a mind-controlling monster from beyond reality that only seeks to unravel creation would have been a good ally let alone controllable. There are probably far less dangerous ways to shape the Council without risking the destruction of all. If anything, I think once Maggie realised how bad things were she backed out.
Margaret LeFay, famous explorer of the Nevernever, is not afraid of taking incredible risks. I agree with you on the backing out part. My theory is that's exactly what she did after she figured out her legion of doom was going too far, and it probably was the reason she got killed.
In White Knight, Harry says to Murphy that should the White Council lose the war the Red Court would take control of the less kind parts of the world i.e. not first world countries - he specifically names Stalin's old stomping grounds. I think most if not all of South America, Africa, the poorer parts of Europe and the Middle East. They might not have openly declared they were vampires but I doubt they would have been as subtle as previously. Their numbers would have swelled, their power grown and they would have become might again. The White Court would tighten it's grip on the first world countries that imagined themselves more civilised than the rest of the world. Perhaps the Jade Court might even have increased it's control in Asia.
Absolutely, but that's not ending the masquerade either. Vampires would want to rule if possible, but they'd rule as "humans".
Mortals are strong with ferromancy...when united. Against a powerful foe that they don't believe in (that comes from their legends), who they don't understand or know much about...I think by the time they reacted it would be too late. Humanity is easily divided sadly. History teaches us this. We never unite for long, and never with much strength. Maybe with a common foe...but then again there probably would be those who imagine they could somehow exploit the situation for their own advantage and would undermine the efforts of the others. Plenty would continue to deny what was happening even if the vampires came out of the shadows, let alone declared themselves rulers. This is why the White Council is important. It's part of why it was established. Because before the White Council was around mortals were at the mercy of the supernatural world.
Fear is a great uniting force. I think an ended masquerade is genuinely as scary for the supernatural world as the big dogs in PT/BG think it would be.
That's from Peace Talks when Harry banishes the Cornerhounds (the Hounds of Tindalos). Chapter 12, page 34.
Seems pretty definitive to me.
See above.
Hmm, perhaps, but I'm more inclined to see that as a one-off mistake unless it happens more.