You should definitely stick to one thread, as it's easier for people to follow your sitch and give more on-target advice.
There's not much you can do about her friend. An "Enabling BFF" is, sadly, pretty much "script" in more than half of these things, and they can be destructive. But until such time as your wife indicates that she wants to end her affair and all OM contact, and come back and work on the marriage, and asks you "What will it take?" (or says "I"ll do anything"), you're in no position to control who she talks to, or what the content of those conversations are.
