Unless I'm reading wrong, the videos aren't gone after 7 days; the key grant is valid for 7 days before it expires (or if it is revoked). Deleting the key, or deleting the video, seem to be the permanent actions that removes the videos; otherwise they are available indefinitely. I'm sure @nathankot can clarify here.

You are correct!

Thanks! The question about long distance sharing is a tricky one, since data on the leaky internets etc. I suppose you could do something via a hop through Dropbox (or equiv) since the actual content is already encrypted. That assumes the encryption never gets broken, but when quantum computers take over the world, a naughty video is probably going to be the last of our problems :).