That said, I'm strongly against burning Korans, Bibles, etc. That's not really a striking a blow for free speech, it's just being a massively antagonistic prick.
Being an antagonistic prick is a valid standpoint. Especially if it forces people to confront their beliefs about the sacredness of things.
On a side-note, burning a book is blatantly not an act in defence of freedom of speech. It's pretty much the exact opposite: suppression of the expression of others.
Book burning, like flag burning, is a speech act. It is stating that you hold the words written to be of so little value that they're not worth preserving. And let's be clear: book burning a book with millions of copies isn't remotely the same as book burning by authoritarian regimes to suppress information. It may be a "fuck you", but it's a principled "fuck you"
It also grabs headlines. And isn't that the part of any protest?
This is not a statement about free speech, it is absolutely a bunch of people telling another bunch of people that they are not welcome and should fuck off "back to where they came from" (which of course for many in this case would probably be Malmo).
I would find that explanation a lot more convincing if the most violent responses didn't come from communities in other countries, far away from the burning. Which happens quite often. Past draw Muhammad and Quran burning events have resulted in deadly riots in countries far away. If you're willing to kill someone in your own country because someone you'll never meet in a country you've never been to burned a book or drew a picture, I think that fact needs to be drawn attention to.
Not that deadly domestic responses are unheard of. The murder of Theo van Gogh by Mohammed Bouyeri springs to mind.
See that is a fine line though due to the fighting words doctrine even in the US. The courts ruled that calling a woman a hussy and a whore was not free speech. Depending on the judge you get it goes back and forth. Honestly though they should just deem behaving that way as fighting words and be done with it because if you are saying something that you deserve to be punched in the nose for then no it should not be legal. Due to too much politicization of the courts though they allowed more than they ever should have. Screaming racial slurrs at people is no more productive than screaming fire in a theatre or in an airport and only serves to incite violence.
Your understanding of the fighting words doctrine is not great. It's a narrow exception that has been chipped away at over the years, not because of any politicization but because the underlying case was weak. And the precedent was bad. Look at
Chaplinsky v. New Hampshire, 315 U.S. 568 (1942). That's where the doctrine comes from, and it was someone prosecuted for calling a cop "a damned fascist". Just like "fire in a crowded theater" came from someone arrested for opposition to WWI conscription (Schenck v. United States, 249 U.S. 47 (1919))
Basically, prior to the 1960's reversal of this trend, the Supreme Court held that through a poorly defined doctrine, you could be arrested for calling cops fascists or opposing wars, and your criticism is that this doctrine hasn't gone far enough.
if you are saying something that you deserve to be punched in the nose for then no it should not be legal
This is a horrifying test that would subject speech to a popularity contest, which completely undermines the point of the first amendment. Popular speech needs no protection: unpopular and controversial speech does.
The courts ruled that calling a woman a hussy and a whore was not free speech
Do you have a citation for this case? Because unless it was a SCOTUS ruling, the decision in Brandenburg v. Ohio, 395 U.S. 444 (1969) still stands.
Also, you can absolutely call a woman a hussy or a whore, if such a statement is true. Truth is, after all, an absolute defense.
You are trying to relitigate something that is essentially a settled issue in American jurisprudence, using arguments that the court has heard and rejected. I would advise not doing that.
I see this all the time, from people wanting to relitigate the New Deal (especially popular among some libertarian legal theorists). They tend to be blisfully unaware that the arguments they peddle were rejected in the 1940s and the caselaw built since then make it about as productive as trying to argue against the iceberg as the ship sinks.