To be honest, you are asking many of these questions before I got answers -.- maybe the social scale may play a big role, may not. It may only ever be a value for npcs to compare their preferences to.
I know, if I was to take me personally, I'd have a social score of maybe 40. But that doesn't mean I want a submissive mate. My mate I'd score at about 30. We make it work. I like a strong willed mate who can challenge my thinking.
It does mean we got to work harder on our relationship as we can butt heads spectacularly.
It's this sort of dynamic I'm trying to emulate and show. Two "dominate" people can still be a match, just more effort will go into making it work