1) Not really, because her contract with him would be temporary anyway (most likely), and so theoretically he'll still have to deal with that when/if he ever goes home. Essentially it just means that if/when he ever separates from a contract with her, it's expected he'll return to pay his debt to his voodoo pals. In that way it's sort of convenient for her, because she likes having leverage on people when she can.

2) Since he's already made the deal for those things, and for ease of play (it's more fun when characters can keep their signature abilities), I would say he can keep his shadow, weird eyes, and some degree of his magical abilities - of course, limited by the fact that he can't make new contracts with the loa, so he's stuck with whatever level of magic he had upon entering. His voodoo magic would probably start to fade over time, but it could be replaced by its equivalent in fae magic as he grows accustomed to it.