Most of that is common sense in general.
The problem is that it sorta' conflicts with having a gun for self defense in the home, and would not go over too well in the US.
If, for example, I accept that I need to have my pistol under tight security, and have the ammunition securely stored also, it undermines my excuse for having the pistol in the first place.
It's not much use for a self defense situation if it takes me five minutes to get it ready to fire, imo. If someone is breaking in, or is already in my house, the pistol might as well not be there if it's locked away behind at least 2 levels of security.
There are ways to secure a pistol and still have it available reasonably quickly. They don't appear to meet those UK guidelines, though.