All the weapons in game have a safety switch on them and it would be a nice touch to the game if they would be able to function, for a bit more weapon simulation/ weapon discipline . (Rifles, pistols and AT/AA launchers), this may also be a nice feature for helicopters and armoured vehicles.

I know people will start saying use the ACE mod blah blah, but what about people who play on public servers or people who do not use mods.

You could have this work by having it like change fire mode or maybe its own key binding?. I couldn't imagine a small detail like this to be to difficult to add to the game by devs, i think it would go along way for hardcore arma fans.