Usually the reason why you can't progress a certain action is because you lack a certain passive. Much of this H game requires a lot of passives to do certain things, much like the how waitress job needed one so you could flash. Even if you made Karryn into a turbo slut, if she doesn't have enough experience in the field she's just a walking meat sack with a gaping hole.
My computer can play this H game fine, the slow down got worse then before now at 5 FPS instead of 15 in v.5f. The workaround with the settings still works,. It's annoying needing to go into settings after every fight but it doesn't take long to 'finish' what you need to do anyway heh.