4 would be a
to me - Condemner is what the "win if target player is eliminated" 3P is named to me (though the name is prescribed and not described) and Treestump is defined that way in Great Idea Mafia
as for my thoughts:
1-shot RNG Cop can randomly be useless
Nymphomaniac really needs a different name but it's still named that in Great Idea
Adder only divides by 2 if the result exceeds the maximum - therefore it tends toward high number roles
Double Roler is kinda stronge
Survivor Compulsive Bodyguard should probably be on Worst Role Ideas
Jester Diplomat is a blacklisted alignment/role combo
I am tempted to vote
0 just for the meme but
4 or
8 would be good actual choices.