True, Your letter is a good one, however, I think you need to sit down and rewrite it a bit so that it doesn't sound like a knee jerk reaction to his posting. The way you've written is a reaction and you do not want to give him the satisfaction of a "reaction". Think about for a day or so and then rewrite it so that it sounds more like a well thought out response, a friend to friend letter at this point. Okay?
As for him wanting a divorce, then he should be the one starting the paperwork and the ball rolling up that hill. He almost sounds like he's trying to push you into filing. I would make it very clear in my response that if he wants the divorce, then he better well know he's going to be the one doing the filing. Also, if he's out there purchasing and selling property right now, you are entitled to half of it because there is no legal separation in place. You are still entitled to half of the property he's been haggling over w/you for a couple of months.
True, as I've stated before, don't give in to this man, not one inch. If you do, he's not only going to take the inch, but the entire mile. You are going to have to rely on yourself and treat anything to do w/finances as a business venture. He's not to be trusted and he's playing those mind games once again. He really is a piece of work.
True, be true to thy self for only you can trust yourself and the good Lord up above.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.