Virtually everything mentioned has allready been looked at by worldwide security. Assume you only have your wits and your body, because someday you will. You allready have the perfect defense weapon in ju jitsu. Just make sure your sensai understands this is for the real world and not a judo match. My zen roshi knew and taught the difference, to the humiliation of a young multiple black belt and grand national japanese champion and a biker type in one afternoon.