Well, Eric, I'm suppose I'm a bit relieved that you were not proposing a catch-all limiting principle for identifying rights when interpreting our own Constitution, but were instead merely "addressing the question of 'would we want to put gun rights in the Constitution if we were to start from scratch?'"
On that second question, I'm glad to say I agree with you -- not because rights should be limited to those that protect against entrenchment of political power, but simply because I don't see any particular normative case for a constitutional right to use firearms for self-defense.
Like you, I can't hope to top Dahlia's skewering of Justice Kennedy's obsession with protecting settlers from those rapacious wolves and bears (and, uh, grizzly bears, too). His reasoning, such as it was, appeared to be (i) that settlers did use firearms to protect themselves on the frontier and (ii) (implicitly) that it would have been unthinkable for the state to have deigned to prevent them from doing so. As you are right to note, Kennedy is correct that a disarm-the-settlers statute would have been absurd -- not because there was a constitutional limitation on such enactments, but instead because there was no particular reason for the state to restrict the use of firearms on the frontier: The problems that confront the D.C. City Council today are just a bit different from those that legislatures considered in pre-revolutionary times.
What Kennedy fails to cite -- and what all of the briefs in the case do not identify, as far as I can tell -- is any evidence that the Constitution was ratified in order to guarantee that such settlers would continue to be left free to hunt wolves in the event some legislature somewhere decided to impose firearms limitations. In other words, the fact that something was (for good reason) largely unregulated at the time of the Founding does not mean that anyone thought it could not be regulated, if and when a legislature found a good reason for doing so. Justice Scalia actually made this point quite nicely a few years back in response to an argument of Justice Thomas that anonymous speech must be constitutionally protected because there was so much of it at the Founding:
Anonymous electioneering was not prohibited by law in 1791 or in 1868. In fact, it was widely practiced at the earlier date, an understandable legacy of the revolutionary era in which political dissent could produce governmental reprisal. . . . But to prove that anonymous electioneering was used frequently is not to establish that it is a constitutional right. Quite obviously, not every restriction upon expression that did not exist in 1791 or in 1868 is ipso facto unconstitutional , or else modern election laws . . . would be prohibited, as would (to mention only a few other categories) modern anti noise regulation . . . and modern parade permitting regulation. . . . Evidence that anonymous electioneering was regarded as a constitutional right is sparse, and as far as I am aware evidence that it was generally regarded as such is nonexistent.
So what was it, anyway, that caused Kennedy to be so fixated on settlers and wolves? I think it might have been an amicus brief by Virginia1774.org , which quoted this excerpt from a 1632 Virginia law: "…But it is thought convenient that any man be permitted to kill deare or other wild beasts or fowle in the common woods, forests, or rivers in regard that thereby the inhabitants may be trained in the use of theire armes the Indians kept from our plantations, and the wolves and other vermine destroyed …"
Wolves, Indians, even "other wild beasts" (albeit no specific reference to grizzlies): It's all there. Yet when I saw this quote, I thought it curious that the amicus begins it with an ellipsis and the word "but." Did the Virginia legislature really mean to be foreclosing any firearms regulation with respect to settlers and wild animals? Well, not quite. A quick Google search turned up this , Act 49 of the Virginia laws of 1632, which reads in full :
" NOE man shall kill any wild swyne out of the forrest or woods ,except in his  or devident, without leave or lycensefrom the Governor. But it is thought convenient that any man be permitted to kill deareor other wild beasts or fowle in the common woods, forrests, or rivers in regard that thereby theinhabitants may be trained in the use of theire armes, the Indians kept from our plantations, andthe wolves and other vermine destroyed. And for encouragement to destroy the wolves, it isthought that whosoever shall kill a wolfe, and bringe in his head to the commander, it shallbe lawfull for such person or persons for every wolfe soe kild, to kill also one wild hogg andtake the same for his owne use."
In other words, the statutory phrase quoted out of context by the amicus is an exception -- a wolf exception! -- or, more precisely, a contrasting authorization, to a general prohibition on killing "wild swyne" without a license from the Governor. Moreover, from all that appears, the Virginia license to kill wolves is not based on any notion of constitutional or fundamental right, but instead on the simple finding that such killing was "thought convenient."
Thus, to the extent this 1632 Virginia law is to be an authoritative guide to the meaning of the Second Amendment (yes, I kid), I think the most it would demonstrate is that if a resident of D.C. brings the head of a wolf to Mayor Fenty, he has a constitutional right to a free ham.