Quote: I don't think SO fully comprehends the reasons why I need to keep contact to a minimum. He thinks I'm being mean, or it's some kind of payback or something.
I would very pleasantly tell him that you aren't going to live the same life anymore, that you aren't satisfied with the situation and aren't going to continue in a situation where you get half of his heart and his love. Tell him this in a very loving way, and yes, I think you can combine this with telling him what you want.
Quote: My biggest wonder is if I've shown him enough of the improved me, expressed things in a way that shows how we could find ways to fulfill what was missing in our R enough - before taking it away from him.
Yes. I absolutely believe that have, and that he really wants it, but just needs some motivation to get there. What he really needs now is to respect you more, and that's the one thing that I think has been missing. If you demand your SO's respect, I think you'll see a change in him.
The LORD is near to all who call on him, to all who call on him in truth." (Psalm 145:18)