or an endorsement on DL after going through NICS check and training. Either that or a purchase permit good for 30 days like Michigan.
That would take care of one and three. Other than providing public sector jobs to run the registry, I don't see any value in registration. I would leave mag limits to what the gun was designed for.
The biggest source of black market guns is largely because of theft, which is why most countries have safe storage laws. In the US there are something like 500K guns reported stolen each year.

Since the biggest problem is drug and gang warfare. The solutions to that is much larger than any gun law. My proposals for that are: end the drug war, get rid of zoning ordnances and other obsticals that prevent good paying jobs to be withing walking or biking distance. A walkable neighborhood is a safe neighborhood. Instead of the school being dependent on local property taxes, equalize the funding.