JATA,
I’m not Selco, nor do I play a Doctor on TV, but I can shed a little light on your concealed carry question.
First let me say that I got paid to carry an ‘exposed’ weapon for a decade.
Choose a weather condition and my sidearm was exposed to it.
A G21 was literally frozen solid inside the holster during a sleet storm.
Long story short, once I was able to thaw the holster enough to get the gun out, it was still completely frozen internally and I had to wait for hours for the gun to thaw out to be able to unload and dry the gun out and relube it.
Another time, a rookie parked our vehicle in a rather unfortunate location, it wouldn’t have been as bad except for the grain silo exhaust system that was being vented/cleaned. The car was suddenly filled with grain chaff and dust. So were our holsters, firearms and everything else.
Not to waste an opportunity we ended up at the range and testing the guns. His HK USP .45 only fired two rounds before choking.
My 1911 got through almost an entire magazine, the AR actually did better than I had expected, firing the entire magazine.
What does this have to do with a SHTF situation? If you are crawling around with your sidearm exposed to weather and unfortunate things, it may not work when you need it. And if you need your sidearm, you likely really need it to work.
Anymore I concealed carry all the time, even while hunting. This way the gun stays dry, clean and ready for use.
Exposed carry doesn’t fit into the “grey man” concept, which to me is a viable concern, especially considering a SHTF situation.