There could be an automatic dynamic or preference between predator/ prey species similar to how the larger vs smaller partners system works. No vore, just innate aggression or submission based on species. 

Basicly, a rack that uses the wormhole/portal technology at each major joint and genitals to allow moving some of the subject's parts around

I have a fetish for balls. Sue me. Anyways, the ability to put a subject's pair of balls in your mouth, and gargle/slosh them around in your mouth. The way Fek makes (almost) everything jiggly, it'd be pretty hot. 

Just kidding, but it would be nice to have multiple sex organs.

having a mechanic where you can display more dominance (hair pulling, head pulling, tail pulling, spanking) or submissiveness (Not using your hands on subject and just moving your hips, playing with yourself) when you are penetrating the subject with either a toy or your genitalia...

Oftentimes a guy will rub his weewee up and down on the girl's clitoris externally before taking the plunge. Should there be the option to penetrate the vagina without having to cancel out the current action (of rubbing the clitoris with weewee)?