1. Not that I know of, but it's just two clicks to the right on the home screen - I usually just leave it running all the time, so it isn't much of a problem.

2. No idea. If I had to guess it wouldn't be harder than the original jailbreak, and potentially much easier.

3. You can use your iPhone/iPod touch's Remote app to control the ATV (the remote it comes with is a pain for text input) [No jailbreak required]