You've been at this a long time and you know exactly what I'm going to say and my comments are all in agreement w/the other posters.
1. Separate the finances asap. Take half out of the accounts and move the money to an account in your name only.
2. Change any passwords that you have to your accounts that he may have the authority to see and/or use.
3. Check your credit report.
4. Keep a close eye on your credit cards and you may even want to think about getting a new card in your name and/or finding a way to remove his from your cards.
5. Make copies of all financial records and keep them in a safe place, preferably a friend's place for the time being.
6. File separately this year.
7. Be sure to call around for a good lawyer.
8. Do an electronic search on line to see what your state says about support, etc.
9. Once he leaves, separate phone plans, utilities, etc.
10. Make sure you are there the day he moves out. You don't want him helping himself to things that you and your sons may need w/o asking.
He definitely has something going on and his replay behavior is going to take off like a rocket once he's gone. The euphoria of thinking he's got his own place and he's free to do whatever he wants w/o "mom" watching and making comments is just going to send him over the moon w/happiness for a while...but he's going to discover later on that life still comes w/responsibilities.
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.