There is no such thing as a 'safe' area in CF. The Eternal star and the Arena are two examples of safer areas but you can still die in them.
Like I stated before, experienced pkers will still fight outside the arena. They may pick a matchup in the Arena though if rp permits them to not kill eachother. Two elf warriors boasting their prowess or something similar.
The only people who might even consider perma-sitting in the arena might be newbs and even they will have to leave at some point. Plus, when they are no longer newbish to rank beyond a low level they will no longer feel the full protection of the arena anymore so perma-sitting there will get them killed quickly.
It might not add much to OUR player vs. player game directly. But to someone just starting CF it is will. It's also a pretty good place to test skills safely.