Dilemna #2: since you have gotten a lot of advice on the first one, I thought I would hit up the second one for you.
You don't owe your ex any explanation. I get that he wants to have visitation with your S31, but it seems to me that since you are the primary caregiver, he can get his butt up and visit. Point blank just tell him you are moving. The rest, i.e. your relationship, is not his business. Its yours.
Im still standin better than I ever did looking like a true survivor feeling like a little kid Im still standin after all this time and Im picking up the pieces of my life without you on my mind..