Far be it from me to tell others what to worry about, but this would be WAAAAaaaayyyy down my list.
First, you need an intruder, second, an intruder that needs to be shot, third, an intruder that needs to be shot and who is standing in line with the tank, fourth, an intruder who needs to be shot who is standing in line with the tank and you shoot and miss, fifth, a bullet that will penetrate your interior and exterior walls, sixth a bullet that will penetrate those walls and still retain enough energy to pierce a propane tank.
It's not a simple matter of odds, to decide what we might or might not worry about, but the odds should play a factor. Those odds are loooooooowwwww.
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.