Now, before you go insane with "If we add third person it will make those Minecrafters think we are copying them again." Well, this third person view is for cameras and ghosting.
Have you ever wanted to just get a picture of youreself with your awesome build? Have you ever wanted to watch yourself dance? I know I have.
So, when you have a camera, you should be able to hit Y and it will change to 3rd person view. Do the same again to change back. For ghosting, hit Y also. This will allow you to watch someone in third person.
For video, you would hit UP on the D-Pad. This would change it to video mode. Hit RT to start videoing. You could also go into third person while doing this. As for the maximum length of recording, I don't know what that could be.