I believe the reason why there is a collective rights theory is because of the arguements of the second amendment.
The amendment is about the militia, that is why the militia is put first in this amendment.
The reason to have the right to keep arms, is so the militia, and only the militia as prescribed in the constitution, has a ready source of arms available that does not come from government sources.
The reason to have the right to bear arms is so this militia has the individuals to use these weapons when the time is needed. So the aim of the amendment is to protect something that is collective, the militia which also works for the collective. This is collective defence as opposed to individual defence, ie self defence.
So take this collective view of the second amendment, claim that it is a collective right, therefore individuals are not protected, only the militia is protected, as it is the weapons of the militia and the personnel of the militia that are protected. Then claim that this means that only the militia weapons are protected and you have yourself a collective right.
Okay, the falicy of the argument is that you need to have individuals with gun, and their right (or duty) to keep them and to serve in the militia protected on an individual basis otherwise the federal government will walk rings around this militia.
The problem seems to be over analysis of the amendment. The term "the people" is obviously collective, made up of individuals and the supreme court defined the term "the people" and everyone was able to make it say what they wanted it to say.
The simple fact is that the founders' intentions on this matter were clear, and anyone looking at what was going on at this time will be clear in the matter.
Take the different versions of the 2A
June 8th 1789
The right of the people to keep and bear arms shall not be infringed; a well armed and well regulated militia being the best security of a free country; but no person religiously scrupulous of bearing arms shall be compelled to render military service in person.
August 17th 1789
A well regulated militia, composed of the body of the people, being the best security of a free State, the right of the people to keep and bear arms shall not be infringed, but no person religiously scrupulous shall be compelled to bear arms.
Being religiously scrupulous of bearing arms is said in connection with rendering militiary service, or a synonym of this is "bear arms"
This was clear that bearing arms was rendering military service and the context of the amendment is the well regulated militia. It is clear that bearing arms was a collective defence. This is what would have been protected by this amendment.
Bear arms CAN mean something different to this, but the founders did not use it in this way. Two state constitutions at the time also had collectiveness within their RBA
North Carolina’s constitution of December 18, 1776
XVII. That the people have a right to bear arms, for the defence of the State; and, as standing armies, in time of peace, are dangerous to liberty, they ought not to be kept up; and that the military should be kept under strict subordination to, and governed by, the civil power.
In the Massachusetts declaration of rights of 1780
XVII.--The people have a right to keep and to bear arms for the common defence. And as in time of peace armies are dangerous to liberty, they ought not to be maintained without the consent of the legislature; and the military power shall always be held in an exact subordination to the civil authority, and be governed by it.
Mr Gerry also came out and said something along these lines too in the First Congress discusion on this matter.
Does it therefore matter whether "the people" is collective or individual in this case? Not really, the importance is that it does not say "the government" or "the militia" it refers to the non governmental mass of the people.
I also don't think the "well regulated militia" part is confusing, it think this is clear, it should be taken in context with article 1 section 8. It is only confusing if you don't know what you are talking about.
I think what is most confusing is not the wording of the amendment at all, but the ways that people attempt to claim that the amendment reads "The right of individuals to keep arms and to use them for self defence, hunting etc, shall not be infringed".
The claim that the first part of the amendment is a preamble is ridiculous. It is as much a part of the amendment as the second part, the reason to call it a preamble is to claim that the RKBA should not be taken in the context of the well regulated militia, when it should.
An individual can keep arms, that does not mean they can keep all arms, nuclear weapons a clear case, it does not mean anything in the way of useage of the arms, it just means the govt cannot prevent you from obtaining them, so the buying and selling and transporting of the weapons, also the storing of them, but the govt can ban certain weapons as long as they do not artificially increase the price of weapons to make them unobtainable. They can also ban hunting, and things like this.
(This is taken without the argument that the govt does not have the powers to do this in the first place, which is a separate matter and i explain it in this way to make it clearer, hopefully)
The bearing of arms does not mean the use of arms, except when under militia control. It is clear that if an individual can bear arms in any way they choose then the parading of arms through the streets would be protected, yet the supreme court deal with this a long time ago.
PRESSER v. STATE OF ILLINOIS, 116 U.S. 252 (1886)
“We think it clear that the sections under consideration, which only forbid bodies of men to associate together as military organizations, or to drill or parade with arms in cities [116 U.S. 252, 265] and towns unless authorized by law, do not infringe the right of the people to keep and bear arms.”
So the basics are, an individual is protected to keep arms, and be in the militia. ANything else may be allowed, but is not protected by this amendment.
There is the issue of self defence as well. I believe that the right to self defence exists, but not purely from this amendment. That the 9th and 10th play a part, but that because individuals have guns, they are allowed to use them (even illegal guns are allowed to be used in self defence legally).