[ That's where I've goofed before by being too brash and sudden with my attempts to implement some boundaries, thus making me look controlling. OMG ThatGuy! What a revelation this is for me. It never occurred to me that implementing boundaries in other than a very slow and subtle way would be seen as controlling.
I wanted to comment on calling your W too. I say, whatever is best for you do! Think hard about it and if it's benefiting you, you don't mind it, you want to do it for the kids,.. great! If however it's over the top for you, dont. It's your W's responsibility to nurture communication and a R with the kids. But you already knew that! Are there times that she initiates contact with them on her own, or is it always up to you and the kids? If she doesn't, I might skip a call or two... to encourage her to pick up the phone. Just so the kids can see her making an effort for them.