Now that is quite the excellent chapter. I figure there're going to be a lot of people taken rather by surprise by Harry's new level of knowledge and ability when he returns to wizarding Britain. I admit, I do like the idea of horocucii (or horocruxes, depending on how you want to butcher language ;) ) that can be used for more or less benevolent purposes; in a way that does go back to that comment in canon about there being no really light or dark magic, just power and the will to use it - though I'd add the proviso that the intent of that usage is as important as the will and power.
I wonder if Ron's going to be put out when he accuses Harry of not writing and Harry tells him that he never responded; this will especially prove true if Harry's letters with Hermione lead to a much closer relationship there.
It will be interesting to see, when Harry returns to Hogwarts, what the reaction of Albus is to his new lack of a horocrux; I daresay that will be a rather telling reaction.
The training sounds intense but quite useful and, at this point, I definitely can't see Harry taking Divination in Third Year, esp. if he's had better training among his new friends.
I'm definitely looking forward to the next chapter and the removal of the horocrux.
I don't know how far the story is going, but I would think this Harry would take Creatures and Arithmancy. Since Hermione snuck in an 11th OWL (presumably Muggle Studies, after taking the subject just one year), Harry might take runes for one year, since he'll already be working at post-OWL levels by then