Closure is nice, but never needed. "Needing" closure will make it harder for you to move on. I have BPD, and one thing from my recovery process that has made my life much more peaceful is "radical acceptance". If you accept that it is what it is and that it is't healthy, it is easier (but by no means "easy") to let go. His ways probably won't change and you probably won't get any closure from him.

Take the job. I am moving to China all alone. It is a bit scary, but I know that it will be so rewarding to start fresh and rewire my habits.

I just got out of a relationship too. I've had many fall apart here in my town. Staying here would only further the distress I feel from all of these situations.