Question: who determines the standards for a federal employee to carry a firearm? Could TSA set those standards for itself, or are there external standards outside of TSA's control that would have to be satisifed?

I'm operating from the assumption that there are external standards --- in which case, attempting to arm TSOs would lead to the massive administrative failure that has been predicted here. But if TSA could set its own standards ... then I'd be in agreement with the rest of y'all that this would be a Very Bad Thing.