It seems to me like you are doing pretty well. You will get different opinions about what to do about answering phone calls, voice messages, etc....
Personally, I don't reply unless they are about the kids. If I do reply, it's only business and I don't ask about anything. I mean, what else is there to talk about? She fired you, took off with the OW. I mean that's all there is...
Let her wonder and ponder where you are and what you are doing. Let her experience her stupid decisions and the ramifications of them. It's her loss.
You are the BETTER WOMAN. Let your wife realize on her own how much she has mucked up her life and how you are not around to take her crumbs anymore. Work on improving you and getting a life without her. In my opinion, that is the only chance any of us have.
The classic mistake that LBS make is "if I go too dark, they will really stop the pursuit." Heck we all think that way. Sometimes doing nothing is the best answer.
But as always, my caveat is - it's only my opinion.... do what feels best for you and one that allows you to continue to move forward and onward.