Register ALL firearms (and get rid of the home-brew, non-serial # stuff). I'd be fine with outlawing aftermarket modification to any firing/internal mechanism. You get what you get off the shelf and that's the end of it.
I'm also for people needing to claim responsibility for their pew pews. 100% support the MI ruling that came down this week. Also support that the owner is responsible for any crime committed with their firearm UNLESS it can be proven that it was stored in a safe/secure manner. Also bring the hammer down on people who store a handgun in their nightstand and that firearm ends up in the hands of a 5 year old who was exploring the house.
Ammo hording is the one area I wouldn't mind something being done, but I don't know how to go about it. I know trap shooters that fire 10,000+ rounds/year. I also know people with "tactical shotguns" that have a similar amount of ammo sitting in their residence collecting dust. They are not the same. But both possess a pallet of shotgun ammo.