Went back a couple of days in your posts. I personally would not be able to do the friends thing with my WH if it comes to divorce. That sounds awfully manipulative to me and selfish. She knows you are not on the same page with regards to your divorce. Sounds like she wants to keep you dangling in the background. And if it comes to divorce, and new woman walking into your life is not going to be thrilled with that arrangement either. Maybe putting your foot down and emphatically stating that is not going to happen would be a wake up call?
You know your wife and therefore the changes she's going through. What are you seeing? What is she suddenly attracted to? How's your confidence level? You don't have to be a bad boy to be confident in yourself - which is attractive. Are you sedentary and she's suddenly interested in an active person? Are you dressing to impress?
Hope you don't mind me intruding, just some things I myself have had to recently pay more attention to.
M:41 H:43 T:26yrs M:19 yrs S:15 D1:14 D2:9 Living together but separated