Hamburg, I thought of doing the same thing as your GF's exH did. And of COURSE I am threatened by the OW getting anywhere near my kids. I have had some very dark fantasies about that. Both of those things are extremely natural. Two families are being destroyed by divorce. These events you describe are natural outcomes. I am kind of proud of your GF's H in a way -- he is fighting for his marriage! My H would say I was manipulative, controlling, etc, just like your GF says of him.
The point is, all these people, including you and GF, are HURTING.
The fact that your W caused all of this is not going to be clear to her. She is in MLC. Your wife is still be in MLC but she is confused. That's MLC. That doesn't mean that the part of her that wants to come back is false. Even if she is not ready to come back or even if you really don't want her to (which I am not sure is the case from reading your posts!). I don't think it's fair to see all these events as manipulative. They might indicate that she is not done baking but I don't think you can say it's all false. There are many of us out here who dream of the MLCer saying those things. I even dream of the OW's husband coming to talk to me or going to kick my H's rear. I am not saying those things are good or the right thing to do. But I think they are all natural responses to the horrible mess of breaking up families.
I think you are confused too. Maybe now would be a good time to read Gordie's threads. I see a lot of similarities with your stories. He took a really different approach than yours, and though no story or player in each story is the same, it might give you another perspective to see how his story played out.
I believe I will see the bounty of the Lord in the land of the living. Wait for the Lord with courage. Be stouthearted, and wait for the Lord.