I suggest making some slightly lesser value asteroids available in the safe zone, and the more exotic ones in the PvP area. That way, non-PvPers can still make money and gather resources, while those who want the exotics can arm themselves and see what they can do. A self destruct device would unbalance the game IMO.
I'd love to mine some asteroids, but I'm not interested in PvP.
Thanks for reading!