At any rate, does anyone find it disturbing (if not unexpected) that there's more lapses of security (breaches) than there are actual real issues?
A breach isn't necessarily a security lapse. A passenger who takes off running when drugs are found in his bag, for instance, would cause a breach.
Also, what is "artfully concealed"? Throwing my Gerber/Leatherman underneath my laptop in my bag?
No, there would have to be evidence of a deliberate attempt to conceal the item ... for instance, putting it inside the lining of the bag and resealing the seam. Or, for example, when scissors were a prohibited item, a PAX thought she'd found a way to smuggle hers aboard by glueing quaters to them, in an attempt to obscure their outline. (It didn't work.) (Why someone would go through all that trouble for a pair of scissors is beyond me!) (Taping your cigarette lighters to the underside of your baby stroller doesn't work, either, although they're no longer a prohibited item, so you don't have to embarrass yourself this way anymore, folks! LOL)
And what constitutes a firearm in the TSA's definitions?
Umm, a gun?
Does this include the people who legally and properly check their weapons as baggage?
Of course not.
I find it very difficult to believe 22 people would accidentally carry a weapon through a screening lane.
I don't. It happens fairly often at the airport where I work. (Just had an incident a couple weeks ago.) Muliply that by hundreds of airports across the country, and VOILA!
I too am mystified by the fact so many people can be so boneheaded! Most claim they didn't know the weapon was in their bag. Do most people store their guns in suitcases? Hello?! Another fairly common scenario is the off-duty cop who thinks it's OK to bring his gun through the checkpoint.