A person does not have the right to take photos of things, places or people without permission...
Before taking photos, it is always best to make sure one has permission to do so.
Interesting thinking - and subject. The lawyers can speak to this better than I am able (it is a bit of a "moving target" these days), but I believe you are wrong about the first point. If it appears in public view, you can photograph it - unless it is
specifically prohibited by law. What you do have to do is use judgment about how you make use of your image. And that can be tricky if you use it beyond what is generally called "personal use."
For example, it is unlikely you could be successfully sued if you
incidentally photograph an unknown bystander who just happens to appear along with your family in front of the Empire State Building, and then post that on your social media internet page. But if you somehow do that with the
intent to cause that bystander some sort of harm, and actually cause it, and the bystander can convince a judge of that, you could have a problem. (There is another standard for public figures, but they have a really rough time in this regard.)
You are absolutely correct about the second point and that is just a matter of common decency, especially when the image contains persons who can be readily ID'd - again, unless that person is considered a "public figure." (politicians, sports stars, actors/actresses, etc.)
Permissions, such as you suggest, also can be a bit tricky. For example, minors generally cannot grant them, etc. And they better be specific, in writing, and properly witnessed. Generally, these permissions need to be written by a lawyer who understands this stuff - not something you casually scribble on a piece of scrap paper and ask the subject to sign.
The OP probably broke no laws photographing the pistol
unless he was clearly advised photography was not allowed on the premises. Whether he broke any laws by allowing "publication" of his photo is a matter for the lawyers. I hope he can avoid that, since the corporation's own employees bear the overwhelming fault for showing the gun and allowing it to be photographed.
Whether it is photographed with a cellphone or the most sophistication professional equipment is irrelevant - except here on the S&W Forum.
