There are no wishes involved, only the answers to 3 questions.

Aelfinns give you answers, Eelfinn give you wishes.

I don't think that the marking she was talking about was physical. I think the "mark" she gave Rand in Falme wasn't a "mark" but more a lover's caress. The mark she is referring to are the territorial marks, as in she marked him as hers but now another chit (Elayne) has marked him as hers. That's why she says "any other is no more than a caretaker whose time has passed. I will lay claim to what is mine openly now". It's her claim (Rand/LTT) that she has marked, at least that is what I've always thought. I think Selene was always Lanfear.