First, let me take the opposite position, with restricted and curated freedom, how do you prevent people from being oppressed?

The speech itself should not be censored, that includes the objectionable things you mentioned. If a country, or a government wish to make some speech illegal, that it should be up to the courts to remove somebody's speech, through a due process and public discourse.

I take a different position on the paradox of tolerance, the issue is sitting idly by, while groups are being excluded. Open debate, and rational thinking, are required by all countries in the world, and all the citizens of the world, to prevent terrible abuses from happening again. My takeaway, is everyone should fight tooth and nail, to prevent any group from being excluded - including groups we don't like.

I've seen the paradox of intolerance used as rhetorical ammunition to silence opponents online, and that just turns into another form of tyrrany of the current ingroup.

To prevent another opressive government from taking hold (like your examples), we have to trust in people's engagement and wisdom, and the open healthy debate of ideas. We can, of course, help people, through economic stability, critical thinking education, etc...

If we say some thoughts are tok dangerous to be spoken, for fear people are too easily lead astray.. then we are trusting that those who choose which voices are worth hearing will always be benelovent dictators.. the one lession I take away from history is that power rarely stays in the hands of the benelovent. Open communication, organization, and free thought is the most effective way to protect a population.

TLDR: thought crime and wrong think shouldn't ever exist, legally at least.