The levels and experience needed for leveling is the same as for players.
Hmm, are you sure? Cause after killing several molerats (120 xp) there is still no lvl up

. Should be at least lvl 2 by now, so i'm a little confused.
Is there a notification after a follower up'd? like in f2 "i feel much stronger now" or something like that?
Ps.: Using 4 Male Trappers