1. Posting racist articles is not violence. It's speech. If someone decides to be violent after reading it, it's their decision and their responsibility.
2. Peaceful protest is in general not violent. It might be trespassing and other property crimes. That would give the police or possibly the victims of those crimes the right to use violence against the protestors. But that doesn't make the protests violent.
I can't help thinking the reason the left is so keen on calling speech violence, is that they want an excuse to commit violence against the speakers. Subconsciously, of course. Motivated Reasoning and all that.
Incorrect.
Important part: "But we should claim the right to suppress them if necessary even by force"
And there was no mention that the group were violent, just that they refused to listen. He mentioned that the group might get violent in the future not that they are, so we must strike them down preemptively.
Perhaps I'm unusually gifted, but I find the line between violence and non violence quite easy to raw. One of the easiest of all lines, really.