1. Is it possible in your view to maintain a constructive ongoing relationship with an ex N/BPD spouse?
For me, it was not something I could do. I was so deeply codependent, and he was so abusive and manipulative, that I had to sever that r/s.
2. Was it worth it to maintain an ongoing relationship with your ex?
I was not running a business with my ex, but if I was, I can see how that would complicate the emotional recovery. If I benefited financially, but suffered emotionally, I might double up on therapy to help me cope while simultaneously creating a financial exit plan.
3. Do you wish you'd done the post divorce differently and if so in what way?
I wish I had handled the marriage differently, but in retrospect, I shot out of my marriage like a cannon because I was that codependent. I think I'm one of the people who needed things to get scary before I did what needed to be done.
4. What communication strategies do you use to maintain boundaries but still show support?
I always treat my n/BPDx with respect. I do things like start every email with his name, and sign every email with my name. I always say please when asking him for information. If I receive information about my son that I think will make N/BPDx feel closer to S11, I send it. Photos, notifications from school. As long as it does not make me feel unsafe, I share information with N/BPDx. All of my communication is by email, so that allows me the distance I need to keep my composure. I try to treat every interaction as a brand new opportunity -- more because I want to model something for myself. I keep my boundaries firm, and I do not respond to abuse, not even to say that I won't respond to abuse. I try to make all my choices about feeling centered, regardless of how N/BPDxh handles himself.
5. How long did it take for you to "recover" and start to feel whole again after your divorce?
Until you asked this question, I don't think I really considered what full recovery meant to me, but I guess I took dating as a sign that I was feeling whole again. It took me 24 months to get there, and N/BPDxh and I were married for 10 years. I had some long-distance emotional intimacy with former bfs before that, so it was a process.
6. Do you feel maintaining contact with your ex slowed down your ability to recover emotionally after your divorce?
I actively sought to minimize contact, so I'm not exactly the right person to ask about this. But I have an opinion anyway

I think the more work you do with a T, or the more books you read to help you understand codependence, the faster you recover, regardless of whether or not your ex is in your life. Once you start to spend more time understand how you function, and learn about boundary setting, assertiveness, self worth, taking care of others, etc. the easier it is to see anyone's behavior from the perspective of a healthy inner life. Including a disordered ex.
My two cents.
LnL