begging the question - what limits are legiitimate? The NRA relies on the Heller decision and the earlier Beard decision, along with their own interpretation of the second amendment, to argue there should be no restrictions on deadly weapons. NO restrictions?
Ref:
http://www.nraila.org/gun-laws/articles/2012/right-to-carry-2012.aspx
Granted, the OP poses hypothetical situations, but they are based on real restrictions in place. For a current related issue, consider the 3rd grader stopped at his Detroit area school while carrying a loaded gun, and he and the gun were removed from school property. Where in the Constitution does it say a third grader can't bring a loaded gun to school?
According to Hannity, Larson, LaPierre, et al, if it ain't specifically restricted by the Constition, the gubmint has no right to interfere. The point I'm seeing is that it is ludicrous to consider having NO restrictions on guns (or "deadly weapons", as described in Beard).