Are there some guns people should not have and some people who should not have guns?

Yes, and yes.

And Congress, or better yet, state legislatures (since Congress hasn't preempted the issue by passing meaningful laws on the issue) should make laws picking what guns are not to suitable for private ownership, who can own them, and where they can carry them.

Once they do that, if someone thinks their 2nd Amendment right has been infringed, they can take it to Court and we'll see if the law violates the Constitution.