Good stuff about Harry working out the wrongness of the wizarding world, but I think you tried to pack too much in. The middle bit, where you had to explain about things chapter 11 particularly, but other places as well, you lose momentum. These places, I feel, would benefit being treated as you have done the rest. I like your interactions between Harry and the others, particularly Hermione and Ginny, and Draco. You were cruel to Ron - ah, well, he deserves it sometimes. I believe you could expand this. Oh, did I mention bottom!Snape was hot?