I think one of the best defense strategies should be implimented at boarding time.
Get out of your seat, Captain, and personally observe the boarding process. You know what to look for.
Remember when the discussions were all about letting durnk and abusive pax on board. The ground staff seemed to prefer to "transfer" the problem from the ground staff to the cabin crew.
This is the same sort of situation. Passengers aren't used to the scrutinty of "The Man" checking them out as they board. Your careful observations could trigger a reaction that would invite further investigation.
As for agressive manuvers or aerobatics, well, I think that's all covered on another thread...