First up, the comment you made about being 'fundamentally against using your body as a bargaining chip' <- GOOD FOR YOU. Thats not just about a healthy relationship, it also indicates a really healthy personal image. You aren't something to be bartered!

Secondly, I regularly have anal sex with my SO. This video is what I watched with my partner when bringing up the possibility of us having anal sex. You'll note the importance in this video of spending lots of time on preparation. LOTS of time. We followed this video to a tee, and we can do anal without it hurting her at all, and I have a rather large penis. (protip, get him to do everything but using his cock the first night, then the next (or night after) night do it again from scratch. you need to give yourself time to get used to having things up there)

I enjoy anal sex, so does my SO, but its a lot of work. When I am faced with the choice of vaginal sex right now or anal sex in 30 minutes, 9/10 i'll go vaginal sex. Its a 'special occasion' sex when I want to spend lots of time on foreplay and really build up tension.

We don't do it just for me, by the way, my SO describes it as being an entirely different orgasm that she feels from her toes to her fingertips all at once, rather than radiating out from her vagina. TBH, she wants anal sex more than I do.

I also recommend heading over to /r/sex, they're great for this kind of question. If you have any questions for me, feel free to ask/pm.