Thanks for the answer and your time very much.
The Fel thing is about choosing them during challenge 3 (hall) and asking them the right questions implies that you are given some influence just before they leave, but the number never (seems to) change.
The only thing on the challenge 2 (rope) i have seen is that Lew counts as the "second" individual in crossing the rope if Ree is hypnotized to cross with. Which can make you lose on some influence.
Thanks.