This is pretty interesting. One question: if Harry has the knowledge from his future self, why does he have to take books from his family vaults (presumably he already knows whats in them -- perhaps you should have him start to take some books and then leave them behind for others he hasn't had a chance to learn yet) and why does he have to relearn languages? He would just learn the ones he hasn't learned yet. If he knows a language, doesn't he know it? The same with the device to absorb information; does he need to use it unless he absorbing new information?
I can accept Fleur and Tonks with Harry, but Hermione should be in there too -- she way too good for Ron!
Nine Horcruxes? Remus said Harry listed 8 but he only listed 7. I know you were thinking of the diary, but it isn't mentioned. You shouldn't presuppose anything.