All that said. it would eliminate those who have longer term issues, a history of violence, violent criminal record, etc.
You're already restricted in what you can buy, carry and transport.
That's the point, it certainly appears to be the exact opposite. It hasn't completely eliminated the black market in other countries, but it has made it much harder. Hard enough that the rate at which guns are used in crimes is significantly less than in the US. Can you buy an illegal gun in Canada, Japan, England? Yes. Is it easy? NO. What's easier? Go to the US, buy a gun and smuggle it back. Not too many drunk ex's and wannabe gangbangers do it.
Your first point.. So would a background check if it is something on record. If its not on record and you snap, reccurring checks still don't eliminate that with yearly checks. It WILL however, deter, to a degree.
Your second point, I should have clarified.. Its already restricted yes, but don't put it into a further chokehold. If someone carries 6 20 round mags vs 3 30 round mags doesn't matter... He will still accomplish his goal. This goes back to my point of someone how is set on committing an atrosity will commit that atrosity with whatever means possible. If he doesn't have a gun, he will find another way.
Your third point. There are black market guns now, and it will be worse in this country if a ban occurs in my opinion. Gives Mexico another opportunity to smuggle something in this country. They already have people, drugs.... Hell, lets add more guns to the list.
Streetdoc, thanks for those posts. Points well stated bro.