I think your main complaint is that you can't see how it could come under the Commerce Clause. Try this...have any of the guns, parts, materials, manufacturing machinery, etc. crossed a State Line? If so, I can see where the Commerce Clause could be invoked. Last time I looked you don't have any steel mills, iron or bauxite mines and very few firearm manufactures in Florida, so how do guns get there? Grow on trees?
This would make it possible for Congress to outlaw simply lying in bed. Anything cross state lines to build your bed? Well, OK, then, get up off the bed. Oops. Anything cross state lines to lay your floor? Are you sure?
So let's say that you somehow manage to make that decision without getting caught. Make a cup of coffee before you leave. Where'd the heat come from? Sure it didn't cross state lines? Got ya there, you're under arrest. Let's not even think about the coffee itself. Coffee pot and cup, made in China?
Maybe you can somehow make it out your door before you break a law. Better not step in your car to drive anywhere. Or even in your shoes. Congress is free to outlaw those things, too. Do they make cars in your state? How bout gasoline? Oil? Brake fluid? The crude oil from whence all these things came? The asphalt or stones or pavers your car sits on?
You can't even get out of your driveway without Congress having the power to make something extremely ordinary that you are doing illegal.
Sound silly? What if, tomorrow, it got decided by some special interest group that too many children were being killed by people driving with burned out headlamps or signaling lights? Just because your lights worked yesterday, don't mean they work today. You roll through a stop sign (c'mon, tell me you NEVER do). You are stopped. Your burned out light is discovered, and now it's a federal offense, thanks to the Commerce Clause.
Fact is, Congress has found a catch-all that they can and do twist into law making silly things illegal. This is, IMHO, a severe abuse of power, and unethical as things come.
Think jury nullification is unethical and an abuse of the power to lie? Well, so do I. But I'm damned if I am going to sit and play nice while those in power play dirty.