Thanks for taking the time for such a detailed response, and it didn't come across as brash. Given your military training it's a different scenario to the Average Joe I would say. I accept your points and liked the comparison of the kid going to get a knife!
If every single person in America who owned a gun was to the same level of training and awareness, I can understand it. I would think not all owners/families are as aware as yours or as trained though.
The point about the government just coming into your homes is the same here. They still need warrants etc. We don't have guns though to keep them out - just the threat of the European Court of Human Rights

You can win any legal case with that!
I've been to America a couple of times but not seen anyone other than Police armed. My mates went to a range in Vegas and most of them did ok, except one who couldn't shoot for love nor money. The other lads were telling me he didn't listen to instruction though. He managed to shoot the ground with a pistol when the target was about 10m away

He is the kind of person who definitely shouldn't be walking around armed.