Some make sense, many don't.
None are well-followed, even the bans on chemical weapons.
Cold, dead fingers. This doesn't happen. There is no effort I know of to target mine-making companies for economic boycotts, and any rule that is not agreed to by ALL nations would be unilateral disarmament. I am not a fan of the philosophy of unilateral disarmament for individuals, and it's been shown not to discourage fascists in the case of governments. Mahatma Gandhi I doubt that he meant a fistfight.