You only need to be intolerant of people whacking others with sledgehammers to avoid that issue. There's no problem with tolerating speech in your example. In general, the problem with anybody who is "violently intolerant" is the "violently" part. So when speech is a direct call to commission of a crime, or a conversation in conspiracy to commit a crime, we do not treat it as protected - but it's not because of violence of the speech itself.