I have made much progress and need to keep the changes going and make them second nature instead of thinking about them all the time. Keeping the M intact is best, but I won't miss this woman at all when she goes. Either she goes and my W comes back, or she goes and stays gone. That's her two choices.
Maybe I'm reading this wrong, but what I'm seeing is "she needs to change". She does. But, if she wasn't having an affair and he was just a friend/colleague, then you were very bad to her.
IDL, the other thing is that your old wife should NOT return. You and her wouldn't be having problems like you did/are if she and you were different. You both need to pull up your socks and build a new, stronger relationship. If either of you chooses not to or you do not like the results of the new relationship, then you leave.