it rewards me with negative passives for doing a "slut run"
There are no negative passives in a slut run. What the passives reduce is damage, defense and the like, things that you will not be using during the slut run.
What they do is increase starting desire and sensibilities, which you want high to access sex actions faster.
Passives are the only way to increase sex actions level, which is what affects sexual damage on enemies.
Eventually some passives will increase sex damage based on desire.
Energy and willpower recover when an enemy ejaculates.
In fact, the passives actually DECREASE energy damage from orgasm and chance to bliss, so you basically treat energy like her HP bar.
More passives make the slut run easier.
The devs said that KP is supposed to be a gangbang game, and that's what you should do, because Karryn can only orgasm once per turn, so more enemies she can pleasure at the same time the better.
The only annoying thing in the slut run is being scandalous, because she will have to fight the entire prison to return to her room.