An agreement is just that…an agreement. If he doesn’t agree to the terms you have drafted and doesn’t sign it, there is nothing you can do to file it with the courts. I am assuming you are in NC and have to wait out the year separation. I would suggest you get an attorney to help you with equitable distribution of property (the truck for instance). If the truck is in your name you can, by all means, “steal” it back and hide it. Just a thought.
Also, if he has continued to call you at work you can file harrassment charges. If you have told him not to call you and he hasn’t stopped he is harrassing you. If he is threatening in these calls you can also file charges for Communicating Threats through the Sheriff’s Dept.