I could comment lots, but I won't. This book was half a story. Most things in it will turn on the wrap-up. The author left herself reinterpretative wiggle-room throughout all the subplots. And recognizing that is the best part of the argument.
One area that does irk me is Harry's mother. We know little of his mother's friends and family. His mother is completely underdeveloped. To me, this is a huge gap in the tapestry of this tale. Since Rowling has so much to do and wrap up in the final book, I just don't see the mother getting the exploration that she deserves.