re: Free speech
Wow, where to begin? You really are unclear on the concept, aren't you?
Burning someone's flag has historically been done by folks who wish to kill those people
Since when? Foreigners tend to burn the American flag simultaneously with burning the current President in effigy. That seems a lot more focused than your vague charge that they "want to kill those people". Fair to say that the American flag has never been intentionally burnt as anything other than a political statement.
Now, the smoke pollution issue, that might have legs. It seems clear even to the most casual observer that wrapping onself in the flag causes brain damage, so QED, the smoke from burning flags is probably toxic. Problem is, only 99% of scientists who've studied the issue agree, and because we're still 1% short of unanimity, we can't possibly act. We need more endless studies of the issues to be absolutely certain, because of course it would be irresponsible to act hastily. For god's sake, it might cost somebody money or something! Horrors!
I fully support local laws charging folks who do burn a flag or anything else with a $1500 littering/pollution violation.
Ya damn Commie! How dare you restrict the freedom of Americans to give in to every destructive whim that pops into our pointy little heads???? Who cares if it hurts other people or imposes a shared burden on society? Damn collectivism anyway!
Besides, any such attempt to impose a flag-burning law through devious backdoor means would eventually get struck down in court (damn judicial activists! Who do they think they are, defending the Bill of Rights and all those dangerous freedoms!).