I’ll put some thought into what you said. But I was brought up with 2 of the big things concerning gun safety being make sure you know what you are shooting at and make sure when you fire, you hit what you’re aiming at. I WILL fire my gun in my home. I’m not sure firing through a wall falls into the category of knowing, seeing or hitting what you’re shooting at. And I’m not real sure I want to fire at a moving car with my child in it. What if I hit my child? What if my aim is perfect, but there’s a ricochet that hits my child?
I also will say that you can’t carry the appropriate gun for every circumstance imaginable. Most of us carry one firearm. And that firearm may be appropriate in one circumstance and not another. Let’s say you plan on carrying a gun based on the fact that you may have to shoot through a car door. You will have something powerful and perhaps be loaded with FMJ ammo in order to penetrate through that car door and have enough energy to kill the perpetrator. But let’s say you are carrying that same gun and ammo combination, but find yourself in an active shooter situation in a crowded store or park. In that situation, your bullet will go right through the perpetrator and perhaps kill someone or more than one person standing behind them. In this case, you want something that will expand and stop inside the threat, not go right through them with the potential of injuring or killing innocent people.
If you always knew what was going to happen, you could always carry the right gun & ammo and be prepared for that situation. But if you don’t know, you should probably carry for the most likely scenario.
Your home is a little different. You can have multiple firearms available and choose the most appropriate. But even if you know where everyone is, you still need to be aware of more than that. I have neighbors. I don’t want to shoot towards someone, have that bullet travel through my walls and into a neighbors house and hurt or kill someone there.
I just think things are much more complicated than basically, carry as much gun with ammo that gives the most penetration as you can all the time. Just in case you have to shoot through a car door or through walls. You don’t always want that much penetration...