RonJon, I have also been dealing with the same thing that you are---only mine has been going on for 4 years. My X and I were married for 20 years when he left and moved in with OW. We have been D'd for about 8 months now. We still chit chat on the phone occasionally. I usually let the X initiate, although I have called him--usually if it has something to do with our boys. His usually start out about our kids, but sometimes he'll call about something else.
I have noticed over all this time that it is easier for him to talk to me on the phone than it is to talk to my face. Probably the guilt thing. They aren't usually oblivious to the pain that they have caused. It's easier not to have to look in our eyes, I guess.
Yes, there have been times when I have told him that I can't see or talk to him. It's too painful for me sometimes--although time is fixing that somewhat. It's painful not to see or hear from him too, and sometimes I wonder which is worse.
As far as being his friend---I wouldn't say that I am his friend--after all, we were much more than friends, and have a lot of history together. I can't act like we were less than we were.
But I am also glad that I kept communication open with him. It makes things so much easier when we have to make arrangements for the boys. He has been really good about taking them when I need him to, and vice versa. It's helped as far as our kids that we get along.
That's not to say that it is always easy, or that I am always willing to talk to him--and when I am in that type of mood--I let him know that I can't deal with him right now. Sometimes it is just too hard.
Anyway, you have to do what you feel is best for you. If that means no contact, then so be it. But, if you do have some hope of ever reconnecting, I don't think that I would close that door all the way. You do not have to make the effort of calling or emailing her--I think that is considered pursuing (which we have been told is a no no). But, if she contacts you, and you can talk to her as if you would a friend, then feel free to do that. As long as you think that it is ok for you. Cut the conversation short if you need to--just try not to be hateful about it.
Who knows why she is calling and emailing. I've spent over 4 years trying to figure my X out, and I still haven't and doubt I ever will.
