I think no matter how many safe-guards you might try to implement in order to prevent the access and distribution of merchandise out of the hands of minors, there will be one of those "super-intelligent" kids as Kokanee put it who will find a way to bypass it.
CJay, I get your point... not even ASC is 100% fool-proof because there is some goofus parent or age-of-majority user out there that will buy something off here and sell it to someone under 18. I think so long as you take the path you're on right now, it will discourage by-and-large the majority of minors who try to acquire an airsoft gun.
Realistically, airsofters should be lobbying this hobby as a sport and strive to one day attaining the reputation it has in countries like Japan. For now, we have to be diligent and spread awareness lest snot-nosed punks wreck it for us. -.-
Honour and Respect... Pew! Pew!