I generally agree with you about everything in this post (and have similar kinks) and love the insight about internal/external conflict, except that I disagree that there are only so many ways an established relationship can be interesting. I could watch Eric and Tami from FNL or Wash and Zoe or Nick and Nora from The Thin Man movies interact forever, and all of them have established, egalitarian relationships.

It's definitely harder to make those interesting, but I hate the idea that it's impossible.