> Further it's possible to opt out of seat belts by not driving and you can kind of opt out of government IDs also by not driving or flying. It'd be difficult but if you really, really cared you could.

Not driving (or being the passenger in a car) is all but impossible in the vast majority of the US. In fact, it’s almost equal to saying “just don’t go to any public places” in response to your gun requirement hypothetical.