Jake,
No problem with what you've said.
What is the non-offensive term we should use to refer to citizens not in the employ of a police agency and those that are? I agree that "civilians" isn't quite right, but for the sake of discussion we sometimes need to differentiate between the two.
I suppose your friend could use his asthma as an affirmative defense against an unlawful restraint charge. I rather doubt that Cowboypreacher could use repossesing a car in the same way.
I still think we should regulate actions, not tools. Unfortunately in many states, as soon as a new defensive tool hits the market, the legislature wants to run out and ban it. Sometimes it doesn't even take that, scary conduct in a movie or TV show is enough to start legislation rolling.
Jeff