Maybe because there already is a training arena in AH. You might want to check it out sometime.
Yes, but anyone can go in, anyone can shoot, anyone can bomb. I suggested that only people of a certian skill level or people with a low KDT ratio, or whatever you wish to use to show someone who could use improvment, could shoot, or bomb, or things on that order, while anyone can go in. It was a suggestion to keep more expirenced pilots from shooting up newbs (they wouldn't be killed, but would keep flying, similar to the planes circling the airfield in the offline arena), and from driving them off. But they can still have a newb joined to them and that will allow them to fire and bomb, and things on that line, but only to demonstrate tequnique and good form.