Great list, this one's a keeper.
As for securing your bags, I have stumbled on a way to LOCK my bags, without locking them, using plain old split rings, threaded through the two zipper pulls on a suitcase or a zipper pull and strap handle on your duffle bags. That way it'll take a potential thief more than a few seconds to open your bags, and when the TSA screenernazi asks if your bags are locked, you can say, No, they're just secured. And if they cut it off anyway, it's only a 25-cent split ring as opposed to a $4 luggage lock.