Regarding 2) Yes, it's just a stupid publicity stunt. There's already tons of photos and videos of amateur baloons and rockets going as high as possible and recording the event. The only necessary piece of information needed from Mike is whether or not he is using a fish eye lens camera for his footage. If so, here's how it will look.

As you can see the curve is created by the type of lens in the camera, as it is the same from ground level to a high altitude. So here's a test:

I hope this helps people realize how much of a difference a type of camera can make.