I believe they are something you have to continually fight for, and that can only be secured by a functional government (which itself is something that requires constant maintenance), vs something you can truly secure for yourself.
And in the particular case of the second amendment, I believe we are in a situation where a "right" granted by our constitution impairs on a right to live freely, free from interference and harm from others, that I personally consider more basic and more essential. The Constitution doesn't have an amendment discussing a right to not get shot, but I don't think that makes it less important.
How is the latter "inalienable" and the former is just wishful thinking? The only answer I can find is "because some people in the 18th century wrote one of them down, but not the other."
The right to bear arms does not negate whatever right to safety you think you have. There are 300 million privately owned firearms in the US. Yet the odds of dying from a firearm homicide are quite small.
You are endorsing human rights abuses by oppressive governments like the Khmer Rouge because that government didn't extend the right to freedom from persecution to their subjects. You are suggesting that it was the Cambodian people's fault for not having a better government that granted them more rights.
"The government didn't extend the right to freedom from persecution" could be worded in any number of ways, such as "the government infringed on the inalienable rights of the people" but the fact that such an atrocity was committed says, to me, that claiming such rights are inherent, natural, or inalienable is rather useless. They clearly can be very easily violated. God or nature is not going to stop the violators, at least not during this life. So what good to the victims is a claim that the rights are inherent and a natural result of being born as a human?
A natural rights framework has the thumbprint of a lawyer along with outmodedly telological way of thinking that can only see a wrong as a "crime" but is willing to construct justifications for what they already believe.
But mixed in the principles isn't just accepting "is wrong because I said so" as a proof. Thus it has contrived post hoc cruft to achieve consistency with assumptions but also underlying ethical principles.
Let's ask a different question: if there are inalienable rights, what is the complete set? Do you expect everyone to agree on what that set of rights is? If one person doesn't believe that guns are one of those, and another does, how do you break that tie? If there is truly a certain set of rights that's a law of nature, should everyone converge on the same set?
Each person has their belief of what they hold to be human rights. As human beings, it is the duty of each of us to protect what we respectively believe to be the rights of our fellow human beings.