I don't think you need to have different addresses and phone numbers, but you definitely need different names. It's because Disney really wants to know who's staying there, not just who's "paying" (cash or points). And you can't physically be in both places, so you need to put the name of the person who is staying there on the ressie, whether family, friend, or renter. (It can be changed later.) Everyone in the room, including the kids, gets a key with his or her own name on it, for entry to extra magic hours and such.