except for #4 the post is great. Sorry about the phone bill, it sucks to see it even if you suspected.
No questions about whether you will want him "if this and that" happen, matter now. I think they take energy away from #5, and the rest.
Detach. The pain will flare up now and then but you'll heal as you can see, you are starting to already.
I'm sorry he's a cheat and liar. Doesn't mean the WHOLE M was a sham anymore than his recall of "being unhappy" is. Detach, let the good times & memories resurface for both of you, and Keep Growing.
I don't know what your h offers OW, if he's being open with you about money.
She'll figure that out. If he's not open with you about money, time will probably tell b/c fil is out of work now, and mil is not nearly the interfering villain your h let you believe. If they're ALL broke, they'll notice his purchases. Can't wait til he knows you saw the bill. Say nothing. NOTHING...if he bothers to explain or lie some more, roll your eyes and show utter indifference. As in, you are Totally NOT interested.... As he is now, at least you know you don't want him. That's what counts. B/c he is who he is, now. Til IF AND WHEN That changes, what's to ask?
Good luck, and let's get on with the rest of your list, esp #5!
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016