" I have an idea how to deal with OM in the right time, right place, on my terms. Punishing W in the process does not come into it. And I've moved into an emotional place where I am ok with this."
This has nothing at all to do with punishing your wife. It is about protecting your marriage. Every time she contacts him, every time she interacts with him it damages your marriage. I hope you see that. There are consequences for adultery. And one of them should be, if the unfaithful spouse wants to remain married, to stop all contact with the other adulterer. It is the ethical thing to do. It is good to know that she plans to do it sometime in the future.
I couldn't care less what happens to the OM, I do think his wife has a right to know that he had an affair with your wife. Have you been tested for STDs?
The paternity test is certainly up to you.
I hope your wife indeed wishes to recover from her adultery and build a stronger future with you. It seems she is being sincere.
I'm a man . . . But I can change . . . If I have to . . . I guess . . .