I'll play...
First, I want a national preemptive act. All state and local legislation pertaining to the purchase, ownership, or transportation of firearms or ammunition overridden, any attempt to pass or enforce such legislation shall constitute Rebellion Against the United States. I could see a proviso allowing state or local governments to prosecute violations of the uniform national laws if the Federal Government elects not to prosecute. Right now, the United States is a crazywork quilt of laws. We need one uniform law.
Second, I want a Personal FFL to replace the Curio & Relic license. The C&R is great if you are buying older guns, but not that great if you are buying newer stuff. And going through a dealer is a PITA if you are buying high-end target arms.
Third, I want suppressors removed from NFA. Require NICS if you want, but the whole NFA rigamarole? I could see rewording the Any Other Weapon category and moving "gadget guns" out of the NFA as well.
Fourth, I want import/export reform. Getting rid of the infamous ATF import point system for pistols would be a good start, but I'd like to see firearm owners have the ability to import arms...and export them for repair. There are several makes of very-high-end target pistols (Match Guns, for example) that don't have much support in the United States. If you need repair work, you're SOL - because the whole idea was that you sent the gun back to the factory. We live in a global marketplace, our laws need to be adjusted for it.