I believe what the thephenom is trying to say, and he/she would be correct in saying so, is that this isn't a feasible idea, largely due to enforcement and logistical concerns. However, it's also not clear what you're trying to do and why you're trying to do it.
Consider that since such a system would be self-imposed, it would have no enforcement mechanism. There's also the added complication of an administrative workload that would be taken on by a select few for the purposes of trying to impose something that would have no clear benefit.
While age verification on the part of ASC is certainly a first step in terms of displaying the value of personal responsibility, anyone could tell you that it doesn't actually accomplish the objective of encouraging it in others, i.e. we can only govern our own behaviour, not the behaviour of others.
Even if we could impose such a system, it is not clear what benefit we would receive. For example, what objective is it that you're trying to accomplish? And if your goal is to take a position on the personal responsibility of airsofters, who are you trying to demonstrate that to? To what end?
If you really want to help the situation, I had provided my thoughts on doing so in another thread