First things first as you're throwing up a bunch of questions that have no relation to each other.

1) Tell your W that since you are leaving for the US in a few hours, when you get back to Sweden, you'll tell W that you will work with her on D. Until you get back from the States, there will be no discussions on D. This way, you will protect yourself from confusing double-talk from W in the next 36 hours. And what's a few more days in the grand scheme of 10 years?

Do I start internet dating (the EE folks have helped me prepare a profile) or go see an old (divorced) girlfriend in Denmark or contact a woman I met on the plane this summer? If this is to the final act, how shall it be played?

My dear Luke...you're getting ahead of yourself. This wouldn't be a good time to start these activities when you are leaving for the States and still dealing with W etc. This is external noise you do not need to add on top of what you're dealing with now. Focus on you for the time being.

I walk tall, generally (being tall helps). So yes, I can do that.

Then start doing that inside your OWN castle in front of W and kids. Do this every day. You're the master of your own domain.