The way to make sure you have the right to talk about people being gay is to fight for those rights by throwing bricks at cop cars, not to trust a bunch of think tanks who say they value the abstract ideal of free speech.
It's certainly true that we also must not give in to BS abstractions about the virtue of free speech to solve all ills. That's also a tactic used to silence people, forcing them into quieter and quieter protests while falsely portraying them as violent. We can't completely wrap ourselves up when we know that they that they're just going to lie about it.
That's a hard line to walk, but calling for violence is clearly over it.
Violence works, and I hope you don't mean that calling for violence is over the "line" of acceptable free speech - where would America be without writings that called for violence?
If there's enough civil unrest then it's much easier for a law-and-order candidate like Nixon to win votes; I'm expecting this to happen in the next election.