I'm all for repercussions to practicing your right rather than limiting the "right" into a privilege in the first place. Like speech, you are "free" to yell "bomb" or "fire" in a crowded theater, but there can be (and are in that case) consequences to such action. You should be free to bear arms however, whenever, and wherever you please, (2A here), but if you harm others due to negligence on your part, then there should be consequences.
Agree
As for training... well, like many things currently... if there were more consequences for being stupid / untrained and harming others, then there would be more incentive to train. But I absolutely DO NOT WANT to have .gov mandated training by "certified" professionals.
Agree ALOT