I subscribe to the whole "this is the best of all possible worlds" thing, so any changes I would elect to make would be entirely superficial, and not worth giving up the people I cherish.
Although, I can assure you that this idea will be in my mind for the next few days. Perhaps I'll come back with a list of things I would change, but like I said: on the whole they would be superficial, and not worth the sacrifice anyhow..