I think the obvious mole is Craig. I also think Mark and Nicole are getting a winners edit. But I don't think Nicole is getting the loser edit, and Mark has a much better winners edit (episode 1 quote where he wants to win for his family, and again last episode).

So I am going with :

Mole: NICOLE
Winner: MARK
Loser: CRAIG

This could also be wishful thinking on my part, hoping for a surprise ending rather than the boring, predictable Craig = mole.