Here is what I see after I click "GENERATE AN ADDRESS" > "Generate an address for any other reason": http://imgur.com/ktTssbB
If I click "Not Now", the prompt goes away and nothing happens. Perhaps I am misunderstanding how the service works?
Ho sorry you're right, technically accepting webpushes is not required, but it's part of the tunnel for now. We're currently changing that, but it's not finished yet.
You'll need to fix that. As other have pointed out: If I'm not a fan of spam then I'm likely not a fan of desktop notifications either.