Hm...Nut...wow...I was just thinking the same thing...I started writing a new letter, one in which I took more responsibility for what happened - and right away I started to see how it could be used against me if she wanted to...while I do know that I have my share of responsibility for the demise of our M, I also know that if I say too much she will use it against me again...I do have to be very careful with what I say to her...so I've decided to just keep things as they are for a while longer.
"The hard part of all this is dealing with one's own emotional pain without becoming vulnerable to attack."
That sums it up very well...and that's exactly why I haven't brought myself to write her/talk with her about us at all...not just because I've gone dark - but also because it's all too easy to be vulnerable to her attacks.
Our MC once told me W that she mistakes anger for power and control - and then went on to tell her that if she really wanted to feel more powerful and in control that she would have to let go of her anger...since she would continue to have it in her, even without me in her life...my W didn't say anything in response - and the MC never brought it up again...which I thought was a mistake.