Oh my goodness, is that your reading of the text? Let's read it again:
A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.
Do you notice the commas in this sentence? That means that we can easily interpret what is being said.
First, we look at the first comma, it seperates the first portion of the sentence from a defining portion.
Why are we talking about militias? Because they are necessary to the security of a free state.
Ok, now that we have that decided, what is the best way to keep a well regulated militia?
The next phrase tells us how. The right of the people to keep and bear arms.
If you don't have an armed citizenry, you don't have a militia. Period.
Since it is important to have a militia, in fact it is necessary to have a militia, you must have people keeping and bearing arms.
The last phrase gives specific instructions on how that is to be handled.
"Shall not be infringed"
That means that it is unconstitutional to infringe upon "the people" being able to keep and bear arms. The reason that "the people" need to be armed is so the free State may enjoy security.
Now how is a militia able to provide security for a free State? Isn't that what the standing military (provided for in Article I, Section 8, clause 8) is for?
Obviously not. This issue of private citizens not having the right to keep and bear arms is after the fact of Article I, Section 8. It is an amendment to the Constitution.
The Constitution, which already allowed the Federal government to raise armies; which already allowed individual States (with the Consent of Congress) to keep troops; was amended to prohibit infringment on individuals keeping and bearing arms precisely because they were not under governmental control.
You keep throwing around the Militia Act of 1792, but the second amendment was ratified in 1791. Militias in 1791, were loosely organized groups of men who, without government say so, organized themselves into military units. An example of this would be the Massachusetts 4th under the command of General Shepard who defended Springfield, MA against Shay and his rebels in 1787.
It was because there were 1200 men who kept and bore arms that Shepard was able to put down Shay's Rebellion.
The founders knew what militias were. They knew that the right of everyone to keep and bear arms was essential to the proper formation of militias.
And to that purpose, they forbid any infringement to that right. Period.
The Founders didn't want an armed citizenry. They wanted a select Militia. They ended up with a well regulated Militia.
Grammatically the first and third commas are superfulous and do not appear in the versions sent to some states, nor in the Official record, The United States Statutes at Large
You have to remember that documents were all hand copied at that point, until they made it to a printer that is. It think the 1st and 3rd commas, which do not change the meaning, were put there for ease of reading, or actually because whoever was copying it thought there should be commas there, for ease of reading.