So, I think I will start with the stuff that bothered or upset me in some form; it shouldn't take long, cuz there's not very much of it.
Overall I did think it was a very good end to the series and tied up most of the loose ends I was wondering about, although thinking on it later I kind of got the feeling that the closer she was getting to the end the more she was just sort of rushing things to get done and skimmed over stuff that could have been examined a bit more fully (more specific examples later). I also felt it dragged a little bit in the middle when they were out in the woods not looking for Horcruxes, not trying to destroy the one they had and letting it make them crabby, not going to Godric's Hollow and basically not doing anything useful. I don't blame Ron for getting impatient, although I did think he was rather a schlub for running off like he did.
So, as for more specific criticisms, I will start with the epilogue. Now, I did like the epilogue as it is. Sure, I would have liked to have seen how the Ministry of Magic got itself put back together and what happened to all the Death Eaters, etc., but after all, the books are all titled "Harry Potter and the blahblahblah," not "The Ministry of Magic and the blahblahblah"; it's always been Harry's personal story, so it was fitting that the ending should deal specifically with him and Ron and Hermione and Ginny and all their offspring and all. So I liked that, I truly did, but I would have liked a little more information, like what are they all doing besides raising kids? Did Harry go on to be an Auror, or had he become too disillusioned with the Ministry of Magic? (And is the new Ministry any better than the old? My guess would be no...) And if not, what's he doing? Did he get a job or are they living off the interest from his Gringotts account? Or is he a stay-at-home dad while Ginny works to support the family (that would be kind of cool, actually, and I think it'd be in keeping with his character too).
More on this whole career thing in a minute, but first I wanna say also that Harry in the epilogue didn't really sound like Harry to me...I don't know how I want to say it, but it just didn't really feel like the Harry I know and love. Which is kind of okay, because you could argue that he wasn't the same Harry, because people change as they grow older and get married and start having babies, so it was okay but it made me feel kind of...homesick, for lack of a better word, homesick for the time we missed (which obviously couldn't have been part of the book; it could be a set of books by itself, and probably really boring books at that).
Before I go on, I want to laugh at the name Scorpius Malfoy. Haha, Scorpius. Also, kudos to Arthur Weasley for promoting prejudice against purebloods amongst his grandchildren. Good job, Arthur; way to be part of the solution.
Okay, to continue with the thread of what-are-they-doing-now-career-wise, what are Ron and Hermione doing? Particularly Hermione; has she given up on the house-elf rights campaign, or is she still working on it? And how's that going?
This leads into the main problem that I had with book 7 and with the series as a whole: she didn't really resolve the house-elf issue, or perhaps issues. Because in GoF and OotP, Hermione was all fired-up about house-elf rights and was in conflict with other characters about it, but she was also in conflict with the house-elves themselves because they weren't very receptive to her message or her gestures, etc. And then they just stopped talking about it and it never got resolved, which I really feel is kind of a shame because I was very interested in that issue. While I certainly don't approve of enslaving a race of people (or beings, in this case), I also don't approve of trying to force a race of people to embrace a particular way of life. From the history I have studied, I know that this almost always ends in disaster. So, while I believe that Hermione's heart is in the right place, her attitude and her actions have seemed a little imperialist to me (wait; imperialist Marxism? oh, there's a paper just waiting to be written there, but I am not the one to write it). But that conflict has never been resolved. From DH all I can conclude is that it's okay to enslave house-elves if you're nice about it and give them gifts and try to save them if your house is attacked by a legion of Dark wizards. But on the other hand, are the house-elves really enslaved if they don't see themselves as slaves? And if their culture involves serving humans, is it really right to try to convince them (or force them) not to? These questions have not been satisfactorily answered or even really addressed, and that frustrates me.
By the same token, I thought it was really scummy of Harry to try to cheat Griphook out of the sword of Gryffindor; that made me really, really mad, but I suppose he has to do some scummy things or he'll come across as too good. Be that as it may, while I'm glad it showed up again at the eleventh hour to dispatch Nagini, I wish that Harry had taken a moment to say, "Hey Neville, that sword really should go back to the goblins; let's take it back to Griphook and thank him kindly and apologize for trying to cheat him." Because if they don't, if they keep the sword, that just seems like a final fuck-you-and-your-culture-and-beliefs to the goblins, which I'm sure was unintentional, but still. You know, I'm not expecting that the wizarding world just suddenly realizes, hey, we really ought to show more respect to our fellow magical creatures and everyone--wizard, Muggle, house-elf, goblins--stands in a big circle holding hands and singing, but a little closure on these specific issues would have been nice, I think.
Moving on, I have to say that Rowling has certainly done a stunning job of killing or maiming my favorite characters: to wit, Fred, George and Lupin. I mean, it didn't bother me the way that the house-elf thing bothered me; it makes sense, in the context of the story that people die, what with the way those damn Death Eaters shoot off the Avada Kadavra like it was no more serious than a mosquito bite. Actually, the thing that bothers me about the deaths of Fred, Lupin, and Tonks is that they haven't really upset me yet. I mean, they happened so quick and so near the end when there was so much more going on, that I just kind of said, "Oh, that's too bad," and kept reading, and it still really hasn't gotten to me yet (except at the part where Harry was in the woods and talking to the shades of his parents and Sirius and Lupin; that made me cry). But Fred and George have always been my favorite characters, so why amn't I sadder about that? I think part of it was that we never really got to see sort of the aftermath of that. We didn't get to see their funerals, even though we got to see freakin' Dobby's funeral, so I'm sadder about freakin' Dobby than about poor Fred. I think (at least, I hope) that when I go back and read the whole series again and see them alive again it will get to me. (By the way, I have come to like Dobby, and I was pretty sad when he died.)
Finally, this has nothing to do with anything, really, but how exactly do paintings in the wizarding world maintain some life? Because they explained that photographs come to life because they develop them in a special potion, so do the paintings use special paint, or potions mixed into the paint? Besides the Pensieve, I think that's the magic that I most covet from the wizarding world, because if you had paintings of your loved ones then you'd never entirely lose them, since they apparently retain all their memories and personality and essence.