Besides their intrinsict freaky dynamic (there's no questioning that Misa and AI are just perverts that enjoy rough sex), a part of their sexual experience is motivated by a willingness for pain as a form of escapism. Having 'vanilla' sex, where they are focused on the emotional rather than the sensual, forces them to admit their feelings. I think it's interesting that they're more comfortable with the extreme; when everything is dialed by ten, there's less emphasis on just the person and more onto what they're doing. Its partly why Misa is slapping the shit out of AI or choking her: she literally can't think. They both love it, but I think this chapter really just hammers it down this tentative escape (from a metaphorical and physical perspective).
It's very realistic on commentary about idol culture. I won't provide surface analysis on parasocialism, but it's funny to me that Waka snitched on Misa because she was tired of banging pervy, old, opportunistic men. She wanted to dethrone Misa out of some fantasy that she can "finally make it out" if she reaches the top. But Misa's downfall has been a prophecy. They easily discarded Misa because she was no longer an untainable daydream. When Waka reaches number one, she'll be subjugated to the same system that callously threw away Misa. However, perhaps her downfall may be significantly worse. The only thing worse than a gay woman is a "used" one.
It makes me giggle thinking that a solution is just career changes, but that would antithetical to the whole point of the story (besides horny sex).