I kind of think liberal!verse Jon/"Stephen" are probably kinkier than regular!verse Jon/"Stephen". Spanking, for one thing, is something I have tried to/wanted to write in Needverse but have just failed all over the place with; I can't see how Jon could possibly pull it off without feeling utterly ridiculous. He'd never keep a straight face. (And, oh my god, now I'm ridiculously happy that there's a universe where I get to write this with the two of them! Yay! =P) Being as, oftentimes, the sub doesn't actually have to (or isn't able to) do a whole lot of talking, I think there are a lot more things they could do since it isn't Jon calling the shots. Rape fantasy, as you mentioned, is another. As much as I can see c!"Stephen" having the fantasy, I also see Jon being extremely uncomfortable with actually trying to act it out, being as he'd have to be the aggressor.

(They just kind of...blatantly ignored the implications of the words they used, which made it all the more sigh-worthy. I distinctly remember a House fic where Cameron indignantly exclaimed that she was a "top". Though that was probably the result of the same language being used in the original creator's fics. [Of course, this same fic that made Wilson a sub and Chase a switch, which, lol no. They were well-written beside that, at least, which was nice.] It was either Did Not Do The Research or They Just Didn't Care, I think, since a generic search for "BDSM terms" will turn up this page, which clearly mentions the difference between bottom/sub and top/dom. So yeah.)