I certainly don't like the "selective incorporation" term used to describe the glacially slow fashion in which the Supreme Court has been restricting the power of the various states to infringe our rights. The Fourteenth Amendment makes clear that we have "immunities" which are a consequence of being United States citizens and I believe that the Second Amendment provides an immunity from infringement.
But I am not so convinced that our Founders intended the Bill of Rights to apply against the state governments. Certainly the freedom of speech protected in the First Amendment was a protection only against laws passed by Congress. I don't know how clear it is that there was no state which had any intention to infringe the right to keep and bear arms at the time of the Founding. But certainly the Fourteenth Amendment changed the situation to bar disarming of the people by the states.
This despite quotations from Mason and Rawle? Not to mention the express legislation used to pass the BoR? Nothing else I can say that would change your mind then.
The FedGov isn't "all powerful", but then again... some Rights were deemed essential to freedom and off limits from ANY form of government. These they tried to protect by embedding them in the "Supreme Law of the Land".