Aristede's clue to Beth was pretty misleading. I don't think that switching bodies with Count Petofi is the worst thing that could happen to me. For Aristede, however, maybe losing his looks would indeed be the worst thing that could happen to him.
Poor Beth. She hears in her head Quentin telling her over and over again, "I still love you." She doesn't know that he was planning to run away with Amanda until Angelique put a stop to it. Beth has no idea that she is ancient history as far as Quentin's concerned.
Why does Magda care about Quentin? As I understand it, the reason she wanted to remove the werewolf curse was because it would affect her gypsy kin. Now that it's gone, I would have thought she'd be all ready to throw a curse on him that would affect only him. It's always good to see Magda again, however - just as it's always good to see Julia again.