"Alcohol consumption by minors IS banned..."
And that protects children from misuse of cars and/or alcohol how exactly?
"Do you mean cars in combination with alcohol because, again, already banned."
So is shooting up schools.
"If you are not mature enough to own a gun, you are not mature enough to vote. I would also require states to raise the legal MJ age to align for the same reason."
Similarly, if you're deemed to crazy to own a gun, should you really be allowed to drive? Or vote for that matter?
"The society that allows you and pretty much anyone else to have guns is, though."
Society has nothing to do with it. The right to ownership is not subject to a vote. Anymore than the right to free speech, freedom of religion...whatever.
"That is a problem. But okay, how about you forget to lock it? How about you sell the guns or lose them? How about you develop a mental illness, a drug problem, some desperate change of circumstance?"
Then why wouldn't you argue that any sort of object that could be used to inflict harm be banned or heavily regulated? And you're sort of making the point in a roundabout way that it's really the people, not the objects, that are the problem.