NycNiceGuy, I'm sorry you're dealing with this and are worried.
for starters i think you have to accept that regardless of what you do, its a possibility she will use this. as an outsider i hardly think it would be the end of the world if she did. i understand youd prefer otherwise. but we live in an age where people use "revenge porn". if its any consolation, if i saw something like this pop up in say, my facebook feed, i would react to the person sharing it, and i suspect thats how most people would react.

I agree completely. I think most people would see it for what it is - a reflection on the person posting it.
Couples have sex, couples have kinky sex, couples take pics and videos of themselves having sex... .this is far from new, and people realize and understand this. While it would probably feel embarrassing and horrible if your ex posted "revenge porn,"
once removed is right - it would not at all be the end of the world.
theres an article on here about how to break up with someone with BPD, and i think part of that would apply in your situation, and my advice to you based on that, would be to be as absolutely boring and distant as you can be in any subsequent contact.
Here's the article that
once removed is referring to:
Leaving A Partner with Borderline PersonalitySome excerpts you might find relevant:
"Gradually become more boring, talk less, share less feelings and opinions. The goal is almost to bore "The Borderline" to lessen the emotional attachment, at the same time not creating a situation which would make you a target."
"Keep all contact short and sweet - the shorter the better. As far as "The Borderline" is concerned, you're always on your way somewhere, there's something in the microwave, or your mother is walking up the steps to your home. Wish "The Borderline" well but always with the same tone of voice that you might offer to someone you have just talked to at the grocery store."