We met about one month ago, he treats me well and respects me, and I feel bit by bit this can develop beautifully

From the first date he was honest with me and said that he was married.. She cheated on him and was playing games with him and she blamed him for it.. so I feel I trust him that the relationship is over

He's currently with lawyers to settle the house and after that's done he can get a divorce because she could sue him otherwise

My biggest concern is where to draw the line of finding what they shared together what he liked and didn't like about her .. and if I have some of her traits..

This is driving me mad.. I'm over thinking it and I really just wanna know from a mature level how to handle this situation