So, should I have to have a license, in order to have GOVERNMENT PERMISSION to own various types of weapons?
That's what Keyes is calling for. Now, square that with "the right to keep and bear arms shall not be infringed"...
The Second protects that power from the feds.
Incorporating the 2nd under the 14th will require that a minimum federal standard of 2nd amendment right be sestablished and enforced upon the states (they will be able to exceed that minimum- but not fall below it).
If that is done faithfully to the Constitution it will be like Keyes envisions here. Advanced weapons will be more restricted, but available.