X SF med, I don't really follow your analogy that the wording of the 2A allows the states to regulate the militia. The militia, is the able bodied people, the state is a government of the people. So putting it very basically, based on your interpretation, the state gets its authority to regulate the people (which is the state and the militia) from the bill of rights 2A, however, yet are failing to clarify that last sentence "the right of the PEOPLE to keep and bear arms "shall not be infringed".
Even viewing it in the context of the time, its still stating the people inherently possess the right to keep and bear arms, and that it cannot be infringed upon.
However, I will concede that if anyone is going to regulate firearms, it should be the state's, as long as it is agreed upon by the people of the state. Which goes along with your ability to move to more friendly states. Or the people to remove their state reps when they pass shitty laws nobody likes. Like what was seen in Colorado after the magazine limitation were passed in 2012.
Where my views on traveling would come into place, I would imagine, fall into the ability of the federal government to ensure regular travel between the state's, and individuals not being forced to face unreasonable prosecution and punishment. I'd have to do more studying in those particular area's of the constitution before giving a full on "this is how I think it can be done" opinion. But i think, in keeping with the color in which the constitution was written, that its a possibility.
As for the "repealing" of the articles of confederation, it is wildly excepted that the ratification by all states of the current constitution, made the article of confederation null and void. As in, this document we agreed to, was not good enough and really left some holes in having a centralized government, so we are making this new one called the constitution, in order to form a more perfect union, because that other document kind of left us holding a bag of shit.
But yeah, a play on words maybe, but the articles of confederations had about as much bite as a toothless grandma, primarily where it came to regulating commerce, debts, and disagreements between individual states. Hints its replacement, and that whole "form a better union" bit. And the articles of confederation were not amended by the formation of the Constitution of the United States of America, they were fully replaced, and done so when each state ratified the constitution, as in "we all agree this document sucks, so we're replacing it with this new one".
At least as I understand it.
ETA:
The Articles of Confederation: Primary Documents of American History (Virtual Programs & Services, Library of Congress)