Most of these references are either thresholds (those trigger certain events, most notably the rewards you get for completing levels), or calls to the value (meaning they're there to send the value back, not to use it or modify it in any manner).
The only stat slutlvl actually modifies is Charm.
Well, it also lowers her desire requirements until slut level 50, is a requirement for some passives and has of course quite a big impact on her behaviour/reactions

But true, no other 'skills' than charm are affected.
how do i get this game mode?!
It's from a mod was not published/finished yet.
is there a way to edit masochism values?
What do you mean by editing?
Raising it ingame? Sure, see
here.
Modding the value directly? Sure, see
here. (second spoiler is for modding sadism value, but it's the same for masochism, just search for
calculateMasochismSensitivityRating
).