I see your point, but as a non-American who's flooded with videos of random Americans walking around supermarkets carrying semiautomatic rifles, I'm not sure what you mean with "tightly regulated militia".
Unfortunately SCOTUS has continually widened the scope of 2A over the years.
> as a non-American who's flooded with videos of random Americans walking around supermarkets carrying semiautomatic rifles
You need to broaden your news sources; this is by no means common, except for perhaps in a few gun-happy states like Texas.
Unlike european countries, the american frontier was a dangerous place where every household needed a gun. Armed citizens existed regardless whether there was a militia or not.
Enshrining this right in the constitution had little to do with frontier safety.
Geez, the stereotypes people spread!
But yeah, there are vanishingly few places in the US where you should expect to be in the presence of gun-toting civilians while doing something as mundane as grocery shopping.
> You need to broaden your news sources
To be fully honest, I don't think I "need" to anything. My life doesn't revolve around having an accurate impression of the US. The image your country spreads of itself is one of loud angry lefties on the coasts and gun wielding red necks in-between. I'm sure that reality is very different, but don't blame me for the bad country marketing :-)
By the way, the archaic meaning of "regulated" means "properly disciplined and drilled". It did not refer to control or supervision by a state.
That still leaves open the question of what levels of discipline and drilling the (federal or state) government could demand of someone for them to be included in the Militia.
It is already accepted that felons and the mentally ill may be prevented from exercising 2nd Amendment rights, so it is perhaps not inconceivable that there could be minimum and maximum age limits, or minimum numbers of training / inspection days for people to be deemed validly part of the Militia.
Whether any such changes would reduce gun crimes, or increase crimes generally, or be politically viable or desirable, are separate questions.
Imagine if the 2A said this: > "A well tailored suit, being necessary to a sharply dressed citizenry, the right of the people to keep and wear clothing, shall not be infringed."
Does this mean that the government now has a right to force dress codes on people so that their suits are well tailored?
Also justification clauses have been used in other contemporary laws too:
> Retrospective laws are highly injurious, oppressive and unjust. No such laws, therefore, should be made, either for the decision of civil causes, or the punishment of offences. (From NH Ex Post Facto Article)
Does this mean that ONLY when the ex-post facto laws are injurious, oppressive and unjust, should that law be unconstitutional according to the NH constitution?
In the absence of the 2A, the government would have the power to ban any weapon (using the same authority they have to ban weapons that are not covered by the 2A today). By contrast, under your proposed fictional constitution, there would be no underlying basis for the government to control clothing generally, so your 2A wouldn't expand or limit the sorts of clothing allowable.
As for your second point, I interpret the "justification clause" as saying that all retrospective laws are ...unjust, and that "No such laws" means "No retrospective laws". The hypothetical of a ...just ex-post facto law is ruled out by definition.