I finished my re-read last night. It's interesting how much more you pick up when you know what you're looking for! (And interesting how early on they suspected the right person, but for various reasons never really concentrated on him.)
There are now lots of people I'd love to know what happened to next, which strikes me as the mark of good characterisation. This is what I'd like to think happens:
Yasmin stays with Katya and Flavia while Katya is recovering, mixes more with real people, grows up a bit, Katya's business flourishes without the constant negging.
Zoe eventually goes back to Yorkshire and gets her life back on track, but becomes friends with Rachel in real life, which is a good, supportive relationship for both of them. (I hadn't registered the first time around how close in age they were - I think I thought Rachel was about 14, which was actually Christy Ross.)
Josh and Pez become better friends and eventually work on something together. (Possibly "genius" Bram could be involved in some way and it does him a lot of good. He does need help though - maybe Prudence? With the right support he could be a Vikas rather than a Gus.)
Kea takes over the ME website (which was probably genuinely quite helpful to a number of people who weren't trolls trying to get inside info), or starts her own, and gets a sense of purpose (the "character" Strike muses about at one point).
Jago gets trampled to death by a vengeful horse. (I would say Christy kills him, but she doesn't deserve to go to prison. The weakest thing about this book for me is that it's hard to forgive a team who turn a blind eye to what's going on there.)
And that brings me to the other big thing I notice about the book as a whole. It's really all about fathers and the damage they cause, isn't it? The spectre of Jonny, as always, this time in the form of Strike's reluctance to see Prudence. The utterly awful Jago and Inigo, one who has already damaged a child to dangerous levels, one who could well do the same if he isn't stopped. The really-not-great Nils and Grant, who seem almost normal in this freakshow, but we'd all be seeing red flags if they were the only parents in the story. Barely mentioned inadequate fathers like Josh's alcoholic dad. Did I imagine it or was there a brief reference to Matthew seeming bored with his child already? It might have been something I read in a review or discussion rather than in the book itself. The nearest things we get to good fathers are Yasmin's and Nicole's (well-meaning, if a bit interfering during the investigation), and by implication Vikas's. It made me wonder what Nick will turn out to be like as a dad - it would be nice if there was a stable, loving, not in the least smothering family in the series.