I was out for awhile so I probably missed some stuff. I just wanted to comment to the question of the dinner invite. I see that you had the voices of reason telling you No, don't do it. When is the last time you extended an invitation? What was the result if you did?
I want to be the opposite voice and say what really have you got to lose? Is your now ex-W going to dash far far away from you. Is your R going to take a fatal hit if you ask her to dinner with you? What is the worst that could happen? Probably that she could say "NO". I argue that DBing isn't solely about LRT and GAL. It's about trying different approaches and monitoring results. Have you tried the approach of offhandedly asking..."have you eaten yet?" and asking her to accompany you and S5?
Maybe she will say no and then be more aloof for a few days. So what? But what if after a few days she asks you to dinner? Or what if she accepts and you have a very light carefree dinner that you both enjoy?
I say that we do entirely too much "non-pursuing" or at least advocating that approach. As far as I'm concerned that was a small area of the book. The rest had other suggestions. Do you really have anything to lose? At least you can show her how well you handle rejection.
Now I'll leave myself open for criticism for suggesting such sacrilege.
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt