The National Guard is not a militia, it's an army. I say this because I suspect you're going along the route of suggesting only the National Guard should have the right to bear arms, or even a militia, but the Second Amendment clearly mentions the right of the people.
And yes, Mass has some stupid firearm laws.
How does requiring guns that are not actively in use be secured, or at least kept out of the way of children impact the right to own or bear arms?
There is a difference between safely storing and using your weapons, and not being able to own them.
You don't need dozens of guns laying around the house where kids (or indeed burglars) can just pick them up for "home defence", so safely securing them when say you're not at home shouldn't be an issue, especially if you're that worried about criminals having guns...
IIRC it's not even a legal requirement to report your guns have been stolen or "gone missing" in many states which is not a great thing.
I remember about 3 years ago seeing one of the NRA spokesidiots who had been proudly telling everyone who would listen that "guns are safe around kids if you teach them they're not a toy" (by teaching them it's fun to
play use them), got shot by the toddler she'd been training to use them, because she was enough of an idiot to leave the gun (that she had to have for self defence) in her purse on the back seat of the car (it's always so easy to get something off the back seat of your car in an emergency), and he pulled it out and shot her in the back.
I don't leave knives, or even just things like cleaning materials around where my niece (and before that nephews) could get them, and I find it hard to understand the idea of people who will leave guns lying around, or argue about the idea that maybe it's a good idea to put weapons you're not actively using/in a position to monitor out of the way of children?
If just because if you're foolish enough to leave guns lying around your house and someone does break in, they're now able to access those same weapons,