Indeed it would be a good idea to understand. I would suggest that the inalienability of a right most concerns to whom the right is granted, and to whom it may not be denied. This by itself does not define what the extent, dimensions and limitations of that right might be. And I think even those who would claim the nearly absolute coverage of the second amendment actually know this, which is why even the NRA is not (at least as far as I know) pushing for the right of citizens to own bazookas, rocket launchers, and guided missiles.
What makes a right a right is not what it allows you to do, but who is allowed to do it. If a right is yours you need not purchase it or justify your need for it. It was that last requirement that killed the New York gun licensing law.
And it goes without saying, I hope, that the word "inalienable" does not appear in the Constitution. We can presume that the founding fathers considered the traditional trio of life, liberty, and the pursuit of happiness to be so, and likely others, but whether they did is a matter of speculation, as is whether they believed all the rights enumerated in the Constitution shared that quality.
What we consider the inalienable rights of a human being, the natural rights of mankind, is a social construct, and not sharply defined, and that is so even if almost everyone agrees, and even if our perception of what those rights ought to be is faultless.
If we're going to be literalist and originalist when we discuss the matter, we must beware of attacking the assumptions of others with assumptions of our own.