All of which has been covered before. You are talking about expanding on that with additional restrictions on lawful gun owners and expanding the "conditions and qualifications" on the sale of arms beyond the existing commercial application (the non-existant "gun show loophole")<quoted text>
Like most rights, the Second Amendment right is not unlimited. It is not a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose: For example, concealed weapons prohibitions have been upheld under the Amendment or state analogues. The Court’s opinion should not be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons and the mentally ill, or laws forbidding the carrying of firearms in sensitive places such as schools and government buildings, or laws imposing conditions and qualifications on the commercial sale of arms.
"There's no rational reason not to also regulate guns, gun ownership, and gun use."
The "rational reason" is nothing you have proposed would prevent criminals from getting a firearm and would only put more hurdles and restrictions on lawful gun owners or those who wish to legally purchase a firearm. Your focus for your laws has been towards the control of the gun instead of on control of the criminal.
Gun use is already controlled as much as it can be...gun ownership...what's to control...? Guns themselves...control how...?