TF, not going to lie, that was a rough read. I can't imagine (I actually I had to stop mid-sentence writing this to fight back tears) how tough that must have been, and I deeply feel for you. I think you handled it brilliantly. I really wish I could just take you out to do some fun things and get your mind off everything! That's what I would do for a friend. Just know that we are here for you, to listen and support.
Now to your WAW/WW. Wow, what a complete fog her head is in. Wants you to pay 1/2 of her clothes and nights out!?! That enrages me. "I don't want you to be my husband anymore, but I want you to provide for me like a husband would." This tells me that your W is a WW, no question. Notice how she let her guard down and told D8 "she just wants to be happy". She went off script after her preparation, and gave herself away! D8 was very smart, as you said, to pick up on it. Good for her. Kids aren't dumb, they know which parent tried and which one didn't.
ANyway, I like your plan. Be there for your kids. Continue to show your WW that light from the lighthouse. But also continue to educate her what it means to be D'd and not have you as a H. Because it sounds to me like she is going to try to cake eat like a heavy-set kid at a cake factory.
M(53), W(54),D(19) M-23, T-25 Bomb Drop - Dec.23, 2017 Ring and Piecing since March 2018