You make some excellent points in your post, and I heartily agree that the right to keep and bear arms is a natural, fundamental, unalienable right, but I also don’t believe that the 2nd amendment applies to the states. The states all have reserved their authority to make their own constitutions as far as the federal gov’t is concerned.
The Supreme Court has interpreted the Fourteenth Amendment (a part of the U.S. Constitution deserving of just as much respect as all the rest of it) to guarantee certain things through the "due process" clause.
My own opinion is that they just didn't want to do the obvious which is suggested by this excerpt from the Fourteenth: "No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States;"
I believe that I am in agreement with Justice Thomas when I assert that the "immunities" of United States citizens include an immunity from government infringement of the right to keep and bear arms.
Regardless of my argument, the fact is that the Supreme Court does apply much of the Bill of Rights to the states using the Fourteenth as justification.
Believing otherwise would allow states to disarm former slaves, would it not?