I liked this. It was dark and disturbing, but not too far off the canon personalities of everybody involved...especially McGonagall. I can easily see Harry saying 'Up yours' to the Hogwarts group, particularly now that Hermione is dead. (You evil bastard, you!)
If you intend to do a second, might I suggest two separate venues...first, with the goblins, as they're the only ones with the wherewithal to help Harry escape Dumbledore's control...'for a reasonable fee, of course', and at Hoggy's where each and every one of the students and staff are forcibly shown just how badly thy balled things up...with particular emphasis on ol' Minny.
Well, them's muh two knuts.
Alorkin