I'm sorry. The more I read, the more I think he is not "in". Putting on his ring would be so easy, and a clear symbol.... but no. And never sending the "no contact" letter, again, if it's what he wanted, he could do it. Letting the anniversary pass with three words of acknowledgement AFTER having a significant discussion about with the C last year. He can't say he didn't know it was important to you!
When he said he wanted you, he agreed to a few things, and as far as I can see he has done none of them. He hasn't made time for you and the kids, he hasn't done a thing about work, no letter, no ring, no passwords, and now no recognition. I'm having a lot of trouble seeing the positives in this.
You know, I wouldn't be at all shocked if there was another A going on... sorry to say. His behaviors seem really similar to what they were then, at least from here. In any case, I don't see him changing anything until you do, and maybe not even then. I'm with you on your plan.