To me, one of the most important things you said was the similarity to other codes of conduct, such as the countryside code. Leave gates as you find them; no litter, fires, running, bombing, heavy petting, etc... ;) This seems obvious now, after years of having the code drummed into us, but prior to this? I dunno. I'm only young. I don't remember. ;)
The ancient monument code will certainly open some people's eyes to what *we* think is obvious.