You're right about Overwatch conflicting, i did forget about that, though it states in the KW Description that it works if you disable Outfit cleanup aswell as resetting stuck people. The Rest works just fine for me though, never had any issues with the highschool feature or the KW NPCs. Cant speak for Error Trap since im not using that.I'd like to comment on these. Nraas mods definitely conflict with Kinky World, and hard. I would not recommend using any of them with KW, because you will have strange and obtuse issues that are hard to diagnose and impossible to fix. Master Controller and its cheats should be pretty safe, but that is it as far as my recommendations go.
Story Progression's various modules will break the NPCs that KW creates (and the high school scenario completely too), Overwatch and Error Trap may break sex animations and "clean up" things needed by the mod and in general spam you with notifications of sims being stuck that are largely just false positives. KW was not designed with Nraas in mind and it shows. The mods will step on each others' toes a lot and tank your performance. KW is much more stable and usable with just the bare minimum (Master Controller) running. Yes, it kind of sucks having EA's almost nonexistent story progression and other issues present, but in my mind it's still better when the sex mod works consistently instead of having issues all the time.