I think you're going too far with the "nice guy"/friend thing. And that conversation sounded like pursuing. I think it would be better for you to figure out what went wrong in the M and then show her by your actions that you've changed.
It sounds like communication is an issues so I suggest this book if you haven't read it: How to Improve Your Marriage Without Talking About It
me: 42 | STBXH: 41 | T: 18 | M: 10 | separation: Jan 3, 2010 | they deserve better: S7 & D4 current thread: http://tinyurl.com/3y8sxcp .: first breathe, then heal, then start LIVING :.