Let her go, Flight. She is ready to make mistakes. Let her. It's really hard, you've been married a while. For me, 15 years.
I was ready to let my W go. She filed a D, and it took 24 hours for her to realize it wasn't the right idea.
Maybe it will take months or years for her to realize that her princess complex needs to be put in a box and shipped down the river. Maybe she'll find OM puts up with her crap.
Either way, it sounds like you're in the right spot. I had gotten to a spot in my marriage that seeing her go would have been hard, but I was so ready to see another side of me, and find love again with someone.
Don't sue the AP. That's your anger talking. No reason to do it except for spite. And if you have money to burn...
M46, EXWW46 M15 T17 D20, S19, D13 M - Addiction since 1998 W EA/PA #1 2013/2014 W EA #2 June 2015... BD 1 Big D talk 9/15 BD 2 - EA/PA disc 10/30/15 Served D 1/22/16 Divorced 5/25/16 (yes, that fast!)