If it’s not, the same card could get passed all the way around the circle until it’s back with the person who played the Action.
A: Yes. Everyone is supposed to pick a card from their hand, and pass it simultaneously, specifically to prevent a single card being passed around.
For example, what would happen if only one person had a hand? If the card pass happened sequentially, there would be no change in anyone’s hand! (And how do you decide who starts?) What actually happens is that the person with a hand passes a card, and everyone else passes nothing, since their hands are empty.
A good rule of thumb is: when in doubt, assume that things in Fluxx happen simultaneously.
See also: We think we broke the game…