I listed a property on AirBnB in late October 2016 and I'm still unable to successfully add a payout method. I had similar issues to what you are experiencing. It would let me add it, but would never finalize. It finally let me add my paypal account (not my payout method of choice) via the mobile app, but now its stuck with a "pending verification" message for several days. I checked with PayPal and there isn't anything to approve or verify on their end.
I have two hosting payouts I would like to receive, but I'm unable to do so because I can't successfully add a payout method. Does anyone have the US support number to call? If I find a solution to this, I will post it for others to see. Sounds like they have a bug in their system.