“How can inalienable rights be alienated? Even if one is coerced in signing a form?”
Easy. They add you to the background check system so you come as ‘denied’ any time you try to buy a gun from a dealer.
Inalienable rights are not recognized in a tyranny. In a tyranny rights are what the government lets you have. I suspect the framers did not envision a secret police force that is dedicated to suppressing the people or they might have made the language of the bill of rights stronger by specifying punishments for government officials for violations of the rights by the aforementioned government officials.