Ping, thanks for answering the question. Those basic questions open up a lot of opportunity for feedback.
I will say this as bluntly as I can for you. Unless you are prepared to be completely honest with your girlfriend about how things progress with your wife right now then you need to back off of the new relationship.
If you can be honest with her and up front and she still wants to see what happens, that is her choice. If you do not provide her with all the information then she cannot make a choice that she feels is in her best interest.
While I agree with the do nothing, be still advice on here. I also feel that being still includes not being in another relationship at this point in time. If you want to see what your xw is going to do and have hopes that maybe y'all can work things out then you need to be free and available to commit for yourself that you are giving your all to it.
There is no parachute Ping, you cannot have both, it won't work....
You have pointed out some things that I like. You are getting a foundation in your religion, good. You are Open to putting your family back together and taking coresponsibilty to the deterioration of your marriage, good. In my opinion, and for what its worth, coming here and looking for support and answers says it all. You know what you want here my friend, you are IMO here to gain validation for what you feel inside.