We once had the same problem with the AC issue. I got a guy from the local heating and air company to come out and give me an estimate for putting a lock box over the thermostat. ::

:: Told hubby, "look, if you REFUSE to give me to GD degrees, I'm going to have a box put on it. Then, you can pay for the box AND the two degrees." He gave up the two degrees.
The only thing I can really say about marriage is that you don't separate b/c of annoyances. Abuse, yes. Irritations, no. And that sounds largely like what is happening. Let me ask you something. . .why let his childish behavior crank you up? I know it drives you crazy. . .but, find a way to play this ridiculous game at his level. He leaves you a note inyour checkbook. . .use lipstick and leave him one on his windshield. Like, "Don't forget to wipe your hiney after you poo poo." He wants stupidity. . .give him stupidity.
I'd also let my T's office know that you are uncomfortable with the situation with him calling them constantly, and let them know you'd prefer they NOT discuss anything with him. If there's an insurance issue, you're perfectly comfortable with them dealing with the insurance company. Just b/c he is the policy holder DOES NOT mean he has the RIGHT to contact your provider. Deal with the Insurance company or ask them to appoint someone to act as a go b/t with him and the t's office.
keep your chin up. . .