PL, if you think I'm going to respond in detail to that, you're crazy, lol.
Anyway, you sound GREAT. The one thing I want to address is the part where you ask if you've failed in DBing somehow by your letter or recent actions. In my opinion, HELL NO. The proof is in the fact that you made a decision based on YOUR needs and YOUR desires and are not afraid of the consequences. I think that DB is all about providing us with a set of tools to enable us to stop reacting to these awful situations we are in and start the business of helping ourselves heal and grow.
The "no R talk" part of DB, IMHO, is mainly to discourage us from dwelling on things, like our spouses or marriage, that we likely cannot affect right now. It is to teach us that when we R talk, we are too focused on the external and not the internal. I think once we begin to understand that, and really make it a part of our lives, it's "safe" to once again begin to express ourselves in the context of the R because at that point we are "ok" with whatever happens.
Much of what WE say in R talks, the ones that happen before we are "ready" is all about trying to get THEM to react a certain way and when they don't, as predicted by Michelle, we are even worse than we are before the R talk. What YOU did was to simply lay out where you are and you did it as an FYI so that he has the info he needs to make an informed decision in relation to you, and in light of what may SEEM to be your "moving on" from him. You just clarified your position and made sure he understood what you still wanted but that your actions would be all about SELF for now and less about the R.
The most important thing is you did all this without concern about HIS reaction. It was all about what YOU want and need. It was done with compassion and out of love.