I think you don’t understand rule number one. It is not telling us it is mandatory to load all guns at all times. It is telling us that we are to assume all guns are loaded at all times and handle them as if they are loaded at all times even if we know they are not loaded.
I was attending an advanced pistol class in another city. The instructor told us to practice dry-firing after class. One student was practicing his dry-firing in his motel room. As you might guess, the firearm he thought was unloaded had a round in the chamber. BANG! Round went through motel wall and through the next room, narrowly missing the occupant.
With me, regardless of my degree of sureness that a gun is unloaded, I will not point it another human, nor tolerate anybody else doing so in my presence. When I need to pull the trigger on my presumably empty gun in order to release spring tension in order to disassemble it for cleaning, I always do so with the gun pointing at a brick wall facing an empty back yard. Etc.
BOTH
Dad use to tell me there is no such thing as an unloaded gun...
but I do believe the late great Mr. Cooper appreciated the fact that a gun should be carried and it should be carried loaded...