1. While I agree Ghost Story was a bit of a let down and definitely felt like it could have been a short story, it did introduce the Ghost plane of the Nevernever. Which I imagine is important for the world building, long term. As you say, it did also give us those character development moments such as the degradation of Molly, the suffering of Murphy, the building of Butters to knight, the impact of Mort etc. A lot of it was showing the void that Harry left behind. It also introduces our new mysterious evil faction, the Fomor. Finally, it was all about Harry learning that actions have consequences (which I suspect ties into the heart of the mechanics of Free Will - you will notice that Uriel finally gets serious stage time and Angels start showing up. This is a pretty big hint to how important things are in this book). There is a fair amount of foreshadowing, and also some discussion on how magic works in a fundamental way. We also get some insight into what really happened with HWWBh, and what Justin was like. My take is that this book will definitely will become much more relevant as the series goes into it's final stage.
2. I could be uncharitable here and criticise Jim about Sanya. But I will give him the benefit of the doubt and argue that it could just come down to the writing. The character archetype of Michael (as Jim often describes) is a pillar of good - the typical paladin. So he is as close to a perfect paladin (without going OP) as Jim could write. He is noble, virtuous, wise and brave and all the other things. It is also that he is older than Sanya. Michael's teacher and mentor, Shiro, was even better (comparable to Mozart) in terms of his abilities and seemingly even more virtuous than Michael. He fills the classic Yoda/Master Splinter/Gandalf role. Michael as the second oldest is more like Qui-Gon Jin/Obi-Wan (Ep 3)/Aragorn role. Sanya then is still quite new (hence he uses things like AKs) and fits the Obi-Wan (Ep 2)/Boromir type role. Butters being both the youngest AND newest is then of course is Obi-Wan (Ep 1)/Early Spider-Man/Luke (New Hope). A bit heavy handed on the analogies, but you get the idea. I think they just fit the molds Jim has made. Plus of course for plot reasons - sometimes you need something done and you only have certain tools to hand.
3. I think what Sarissa owes Mab is complex - and boils down to a mix of protection and healing. Remember she had a terrible brain illness that Mab saved her from. I wonder even though she is Mab's daughter, if Mab could even heal her daughter without extracting a payment. I suspect not.
4. As some have already pointed out, Demonreach is in the middle of a lake and quite protected from such events. But even if somehow a tsunami did occur, as has been already stated, the Well is actually deep below the island. Perhaps below the bottom of the lake too - if Harry's description in CD is anything to go by. And I am sure the Merlin put some protection in for just that sort of frontal assault. An interesting note though is that Jim has been rather inconsistent on the Water issue with magic. I suspect when Jim first built it in, like happens to us all, he didn't fully consider the implications. So he has to go back and correct, and because he is clever and experienced he often does a very good job. There have been plenty of scenes where it has been raining that haven't affected magic in that scene. Just look at Skin Game when Uriel shows up. Perhaps Dresden's knowledge is incomplete, perhaps the degree to which this affects magic is undefined. Mostly it is used for plot reasons anyway - the water issue.
5. A most interesting question! Not that the others weren't, but this is trickier. Harry states that there is roughly 1 wizard talent per million humans. So roughly 7700 Wizard-level human talents out there, give or take. But as we know, the 200 Wardens (during and previous to Dead Beat) were about 20% of the White Council. Which obviously puts the Council at around 1000 Wizard. We also know that the Council cannot keep up with the amount of new Wizards popping up as the population has exploded. This also does not seem to include Paranet-level practitioners, but may include Warlocks and Sorcerers (in the 7700 number). Now perhaps Jim forgot he wrote that (he has admitted to that in the past - hence why he checks the wiki and has his beta readers) but I think not. It is also not clear if by the 1000 or so Wizards of the White Council includes apprentices. Which again, I believe it does not. It seems somewhat implied that a lot of apprentices got elevated to full-wizard after the events of Grave Peril in order to replenish the ranks (Ramirez and the younger wardens come to mind). But yeah, I would say that there are not many in the actual Council. Which actually seems really odd - considering the size of the threats out there. A lot of the way Harry used to talk about it made it sound like there was in fact several thousand of them. Harry is massively out of the loop as the series stands, so Peace Talks will hopefully help answer that question (and all the many other overdue ones about the what exactly the White Council has been up to).
6. I can't quite remember exactly, but I believe there is a WOJ on Fae's dying in the mortal world. Essentially it stated because Fae are of two worlds, they don't turn to ectoplasm. However unless they had a mantle, they do not come back. The title of Eldest is normally passed on (like a mantle, yet not a mantle). Fae are seemingly grown from seed stock peoples, so I don't think the younger Gruff brothers will return. Which I imagine Titania isn't super pleased about. In fact, I am surprised how calm Eldest Gruff is. Although I think there are more small and medium Gruffs, than just what we saw.
7. Ah yes. Mother Winter. Why indeed would such a being need a walking stick? Or indeed a body? She is more equivalent to a star or blizzard on a thousand worlds. My guess? The "walking stick" is like the mantles, a part of her. Perhaps the physical representation of her ability to interact. Mother Summer always seems more mobile, and has no walking stick to speak of. When it comes to the Nevernever, and especially the Powers, I believe that we are entering the realms of metaphor as much a physical reality. Abstract concepts such as thoughts and time can have physical representations (which is really what the Mothers are, after all). Remember the Outer Gates - Harry's mind can only process so much so he boils them down into something as obvious and simplistic as those massive gates. He cannot experience reality in more than 3 or 4 dimensions. Same with when he was in Ghost Story, he can only experience a very limited view of reality. The Nevernever is very similar to the Immaterium of Warhammer 40K, where thoughts become reality. Jim used to play both types of Warhammer I believe, so I am not totally surprised.
So to get back to your question - why does she feel pain, or appear old etc? Because that is the best representation of WHAT she is, and how Mortal minds have shaped her. Consider the fact that Harry hurt her at all, and how both angry and insulted she was. Consider Uriel's reaction when Harry dropped the -el from his name. Mortal Free Will seems to have unlimited power in some deep ways...and Immortals hate it. Mortals can constantly redefine their reality, and of course themselves (to speak of one is to speak of the other really). Immortals have only the illusion of this. I suspect this is the crux of Lucifer's argument with God: Mortal's have unlimited power in a sense, and can change all of reality. Any mortal. All of them together...leads to a massive problem. Immortals were only given limited will (enough to act somewhat on their own - Jim has said Angel's at least had enough will to Fall) but cannot really change their own destinies. Why? No idea. Jim may have an answer for his series - but people have been trying to answer question like that forever. So this is why she feels pain from moving - she has perhaps lost the part of her power that allows her to interact more freely. Anyone would be upset by that - imagine if you lost your legs and then some fool tries to drag you out to him!
Sorry about the ridiculously long post, but you ask big questions!
