You have a complicated, messy, situation, and I cannot presume to give solid advice. But here's just an idea to consider:
Given that you are very likely dealing w/ someone who has a serious mental health disorder ... (1) you may want to be really careful about engaging this person in a rational fight about your divorce conditions. If her BPD is real and intense, you are battling her emotional demons, not a rational person.
(2) Your son's situation sounds very messy, and can complicate your divorce process. Can you pause your involvement in that issue, and sort it out AFTER the divorce? Your son's character/personality issue is not something that can be changed in a few months with some prodding. It's likely going to take a long time.
Like I said, just ideas. I hope you have a counselor, and a few good and wise friends who can help you navigate this. It sounds awful.
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final