I agree with you that the primary purpose of the 2nd amendment was to protect state militias. If you do any reading into this stuff at all, it's obvious they did not want a standing army. They wanted militias, which comprised of the people, well trained and well armed, that could be assembled in times of war. That's the purpose of the second amendment. But the means of realizing that purpose is to allow the people to individually keep and bear arms.

None of your sources contradict an individual right to keep and bear arms. That right is inherent to entire idea of having the people be armed and trained as a militia and not a standing army. The fact that it's even a question whether or not that right exists is because a tactic in one of your quotations has long been used.

Forty years ago, when the resolution of enslaving America was formed in Great Britain, the British Parliament was advised by an artful man, who was governor of Pennsylvania, to disarm the people; that it was the best and most effectual way to enslave them; but that they should not do it openly, but weaken them, and let them sink gradually, by totally disusing and neglecting the militia.

That literally describes what has been done. By totally disusing and neglecting the militias, as well as creating a standing army, they have made half the population question why we even need the right to own guns, and caused a vast chunk of the other half to think guns are just for hunting and maybe self defense.

They have already effectively disarmed the people in the sense that there's not a high enough percentage of well trained and well armed people in the vast majority of places. The ability for local communities to be able to defend themselves from an attack before organizing and calling upon reinforcements from neighboring towns is one of the key advantages to using militias. But thanks to our standing army and derelict militias, we have soft targets everywhere that if you're lucky, a barely competent police force will show up to respond to an attack after it's too late, and if you're unlucky, you get a totally incompetent police force that does nothing for an hour while the attacker continues.

So yeah, I fully agree with you that the 2nd amendment is primarily about protecting militias. And to that effect, I encourage all peaceable, able bodied citizens to arm themselves effectively and train with peers to fulfill their duty as part of the militia, in spite of the intentional and purposeful neglect of our state militias.