As for the straw man question on the 4473, there’s a whole grey area there. Suppose you buy a shotgun and decide after shooting a couple of rounds of skeet with it that the stock doesn’t fit you. A buddy of yours tries it, likes it and offers you a good price for it. Maybe you even make a few bucks on your buddy. Does that make you a dealer? No, it doesn’t, even if you only owned the gun for a couple of days.
Who’s to say what your intent was when you purchase a gun? Sure, there may be some pretty clear examples where this guy was buying for the sole purpose of resale. In that case, he’s screwed, but it just goes to point to the absurdity of the gun laws.
I’ll give you an example. A few weeks ago a local dealer blew out some shotguns really cheap. I was tempted to buy them, knowing that I could make $100 or more on each one reselling them. I finally decided to pass and told another local dealer about the good buy and he went and bought them. It was only after the fact that I realized that had I gone ahead and bought the guns for the purpose of resale I would have been in violation of federal law.
You could go on doing this example forever as long as no problems occurred with any of the firearms you originally filled out a 4473 for in your name. Once one of those skeet guns turns up in a Mexican gun fight and they run a trace back to the dealer you bought it from your trouble starts.
The whole thing is really a bunch of BS and IMHO is designed to be able to make anyone into a "process" criminal if the Feds don't like what you are up to, even if you are following the law.