It would go a long way to solving a number of issues we face with the ongoing epidemic of death and injury we in the US face.
That said, as the gunners oft repeat, law abiding citizens aren't the problem. As I've tried to point out in this series, the issue is the increasing lethality of weaponry commonly available over the counter at American gun stores. Law abiding gun owners are law abiding until they are NOT. Sandy Hook, Pulse Nightclub, Las Vegas concert, Walmart El Paso and 80% of other atrocities were performed by 'law abiding citizens' who presumably could have met all the people control you have spent so much thought on.
It is clear that no amount of well intentioned legislation, education, licensing, background checking is going end the violence.
With all this in mind I have come to the conclusion that we need to simply limit the lethality of weaponry available. Australia has done so with very good results. Semi auto guns of any type are not available there, neither are any rapid loading guns like lever action and pump action.
Sandy hook, 500 rounds in five minutes. Pulse Nightclub uncounted rounds in first 10 minutes. Las Vegas 1000 rounds in 10 minutes. What if all these shooters were limited to five rounds in a fixed magazine bolt action rifle?