It's been my experience that any time you think you've got women or TSA figured out, you're in trouble. I've done a lot of flying, usually carrying some sort of stealth blade I shouldn't, but not with actual knives. I've had a few confiscated, it's to be expected. They've tried to take small screwdrivers and pliers, even flashlights, you never know what they'll go after. Knife handles are legal, a bit suspicious, more so in your pocket than carry-on.
Luggage theft usually only happens if it's easy and convenient. They might make an effort for something that stands out. Locks on your luggage stand out. Locks also catch and break on the conveyors all the time, sometimes ripping your zipper out. Luggage thieves usually just unzip, feel around inside the bag, and zip. I've always used zip-ties to secure my zippers. They're cheap, subtle, and unlikely to fail. Of course, you need a nail clipper or knife to remove them yourself, but there are always ways.