Eric - sounds like you are doing well and are in a good place right now.
If she compliments you, yes say thank you. One thing I have determined through all this is MLC or not, I am still going to be a pleasant person. That is who I want to be. I do occasionally tell my H he looks nice when he is dressed up more than normal but keep it very simple. I personally don't see any reason not to as long as he doesn't seem to react negatively (and he doesn't). If it caused a negative reaction, I wouldn't.