I'm disappointed you feel you have to adopt such an overly formal tone. Throughout this process I have been cooperative and reasonable despite your affair and your continuing behaviour toward me.
Since I have known you I have always wished you to be happy and have tried to support you in your decisions. Whilst i cannot agree with your decision and will continue to believe that our marriage was perfectly fixable, I recognise that this decisions is yours to make. I have not and will not seek to obstruct or hinder it in anyway.
I know that this is a difficult and stressful time for us all but please be assured that I will always act in the best interests of D3 and S1.
First paragraph:
You're wagging your finger at W for being "formal" and calling out on her so-called bad behavior. Are those loving and neutral actions that will draw back W? I think not.
Second paragraph:
You're trying to pled with W that M is 'fixable' which isn't attractive. Furthermore, W is already checked out of the M. Why bring up the "blocking" and "obstruct" words which is, in W's eyes, a tacit admission that you have been/are doing this.
Third paragraph:
Whoa! The implication dangling in the air is that W doesn't have the kids' best interests at all. That'll be the fastest way to make her get pissed off at you. Just more negative view of you.
In summary, this email needs to be binned as you Brits tend to say. It is as useful as a three-dollar bill.
DO NOT send out the email. I'd start a completely new one that is 2 paragraphs long. That's it. KISS and STFU.