I agree with dogbertcarroll review of things to happen and would love to see how Hogwarts would treat a prodigy which they would think Harry was instead of a time traveler.
I think he is wasting time retaking classes when he should test out and go for his Masters. Sure it would be suspicious but couldn't he say he found a trunk with his mother's old books? He died because he wasn't ready for LV who has sixty years of knowledge on him.