This training idea is basically good thinking, but there's no way that it'd ever be instituted. From a foreigner/ outsider's perspective I can already see the outcry if it came into effect tomorrow (by virtue of magic wand)
"I'm not going to listen to some pencil-neck govt. paper-pusher tell me how to use a gun"
"I grew up around guns, don't tell me how to shoot"
"The dinosaur people will implant you with a microchip when you go in for 'training'"
The last one is because I'm tired, but still the whacko brigade will still ignore anything even in the community's interests.
@batwatch as you said, to a lot of people guns are inherently evil, which is stupid. But on the other side of the coin to a lot of people guns aren't serious items. As an example, I read yesterday about the guy shooting down his neighbour's drone because he thought it was a "CIA surveillance device". Putting aside the loony part, this guy had put a number of holes in his neighbours house because he didn't care what happened to the bullets that missed. Even when shooting at his neighbor's property was mentioned to him, he didn't care.
Honestly I don't see any solution, the genie is too far out of the bottle over there...