I'm fairly certain you could do the exact same thing here in Canada. I honestly don't think it's as exceptional as you're making it out to be.
What? You have no idea what you are talking about.
What? There's lots of antifacist/rather left-wing music that heavily critizes the police and their work. Usually not the one police officer himself but rather the institution as being part of a state who behaves injust (is that a word? non-native here...). I think that's fine and is part of a democratic system.
Separately: saying something shitty or unpopular that you disagree with isn’t someone abusing their rights to free expression. Expressing unpopular viewpoints that others consider abusive is exactly the point of such rights.
There’s a REALLY BIG reason it isn’t “freedom of expression, except for expressing racial hatred”, and it’s not because we like racism. Germany sometimes bans entire political parties that they declare unconstitutional. Now imagine that power in the hands of Trump. You can see what Putin did to Navalny for a preview.