I understand the "we are very good as friends" line is often typical WAS script but for a while now, I have felt in your case it is almost a form of brainwashing.
Your W is a smart lady. IMO (which I realize means jack) she harps on the " we are GREAT at being friends" angle as she knows you want more. She knows you have spent nearly every waking minute looking for clues on how to create more than "just friends". She knows that quest keeps you very occupied so she continues to hammer that point home so you stay busy.
Again IMO (again, means jack) EA's are FAR more dangerous than PA's. IN an EA you can create an image of absolute perfection. In a PA eventually "real stuff" comes into play as nobody can hide from life day in and day out. But an EA allows for ongoing fantasy that a PA doesn't. If I had to bet I would say yes, your W is heavily invested in an EA and has been for some time. She is just getting smarter about it and has become very skilled at keeping you busy.
Her going back to "good mothering" could be out of guilt, desire, her thinking she is covering her tracks better or once again, to simply throw you off the EA track.
I know this opinion is not totally popular but I am of the school of thought that affairs do NOT end as quickly as most people would like to think. My H is still in his affair two years later and the R is riddled with problems, the R is causing him work issues (they work together) and he lost 80% of his assets and there are no signs of the affair stopping.
I also feel when the WAS who is invested in an affair of some kind starts to "throw bones" the LBS often puts too much stock in bricks coming down or the "fog" ending. Not so. It means they are getting smarter (the WAS that is) and once again, keeping you busy with silly little gestures of hope.
IMO the best thing you can do for you is to go dark, *really* detach this time, end your search for the clues you seek and let her be.
