I believe Dumbledore and the others that set Harry up should have received far more retribution for manipulating a group of 11 year old students and leading Harry to face Voldermort while being relatively uninformed of the situation. Earlier in the story, people were claiming they were going to be a resource to help protect Harry and would not leave him alone, even if they didn't directly interfere. And yet, these same people helped set him up and lead him into danger. It is your story and you are free to choose how the story flows, but I dislike stories in which people are manipulated and not all of the manipulators are punished accordingly.
Other than that, it was a decent story... not the best, but better than anything I could do.