I should note, I'm a little concerned as to how to respond as I don't want her to turn vicious since the divorce is still pending. I fear if she becomes angry, she will get ugly too. But I do need to establish a boundary here. No Friends... All or nothing I think is wise
UGGG!!!!
You are a little concerned?
Why?
Didn't she cheat on you?
Why do you attribute so much value to her when she attributes so little to you?
Maybe that's a question you should ask yourself.
As for the friends bit, seriously, if you want to be friends and you are happy to just be friends and you won't be trying to talk relationship talk with her and try to convince her to remain married to you, be friends with her. If you can't just be friends with her (and I'm guessing this is the case), then end it all. Be civil with her as far parenting your kids but you don't have to be friends with her.
I suspect her being friends with you is her way of dealing with the guilt of breaking your heart and cheating on you, mind you I could be wrong, no one knows, let us know if you get a good look on the inside of her head and you can tell us for sure ;-)
I personally have higher standards for the friends I keep, none of them have used or abused me, cheated on me, etc.