While your reading of the second amendment is one possible interpretation, it is not the interpretation that legal scholars have settled on and the courts have affirmed. Moreover, many people have are other common sense reasonable requirements for weapons, primarily in rural wilderness areas where bears, coyotes and mountain lions are commonplace threats both to domestic animals and to people, especially children. Even in suburban areas coyotes, and to a lesser extent feral canines, pose a threat to pets and vulnerable people, especially small children. A young woman in Canada, a singer, was killed by coyotes while walking in the woods. A number of small children in California have been killed by coyotes. Coyotes are moving into suburban populated areas now, and even into cities, where they kill many small pet dogs and innumerable pet cats. Coywolves, a coyote wolf hybrid, are a serious and growing threat to pets and children. The idea that only people in a militia or in the military need weapons is poorly thought out and is not the court-upheld interpretation of the second amendment.
However, it is also clear that the right to bear arms is not unlimited and open-ended. A person is reasonably prevented by law from stocking a garage or a rooftop with anti-aircraft missile launchers, for example. There is no magic line that puts assault rifles into an acceptable category but renders a bazooka or missile launcher unacceptable for private ownership. Clearly many weapons exist today that were not envisioned two hundred years ago and that are not necessary for any reasonable and prudent defensive purpose. It is equally clear that the founding fathers would not have intended that persons declared legally insane be entitled to bear arms. People should not go hunting while drunk. People should have safety training. Guns should be fitted with safety mechanisms where feasible. There are reasonable restrictions like these that we should all be able to agree on. We the people have the right and indeed the responsibility to regulate the use of arms in a reasonable way that ensures the safety of all citizens.
In modern times arms manufacturers have, for profit and out of greed, done a great deal to promote wanton proliferation of gun ownership without reasonable precautions for public safety. At one time the NRA stood up for reasonable safety requirements, in particular for training in the use of firearms. Responsible gun owners need to retake ownership of the NRA away from unprincipled arms merchants devoid of social conscience. Polls of actual gun owners have shown that they overwhelmingly favor reasonable gun safety legislation.
We need training and licensing for guns similar to what we insist on for automobiles.
It is not written anyplace that the right to bear arms refers specifically and only to guns. We have overwhelming and indeed burdensome restrictions on knives. Why? Because the knife manufacturers are not making the obscene profits that gun manufacturers make, and hence there is no influential knife lobby. Surely a car can be used as a weapon, and indeed they sometimes are. No one proposes that car ownership and operation should enjoy the unfettered access afforded in the case of guns. The fact is that the wording says "arms", it does not say "guns". We have the same right and responsibility to regulate guns as we regarding any other artifact that can be used as a weapon.
But the militia bit of your argument is totally bogus. The courts have ruled on that long ago.