Just my opinion, but I agree with your thought of maintaining your course of D as it is. Right now your wife is cake eating, as you seem to understand, and she will continue to do so while watching what you do. You have set a boundary, and must stick with it until she really goes NC and agrees to create a new marriage with you.
The OM sounds like a creep and it will not work out for long with your W, if she try's to make a go with him. When (not if) it crashes and burns, I'll bet she'll be back at your doorstep asking for you to take her back. I suggest one of your conditions for R is that she quits real estate.
Good luck to you, you seem like a decent guy. 40 seems like a magic number for affairs to start.......
