To any lurking good faith lemmy users who want to ask questions about socialism, you may do it in this thread, I will protect you

but it just bugs me that at the end of the day, whoever is in power gets to define "intolerance" and their definition might not match the majority's. And the majority might not be right either...

This is to me one of the most primal liberal problems with thinking about politics. No, communists do not support some benevolent autocrat delineating acceptable speech, it must be democratically decided with a mind to Marxist analysis. "But what if people vote wrong?" Campaign against it! Educate them! "But what if people vote so overwhelmingly wrong that such a campaign is hopeless?" Then you are talking about a state that is so overwhelmingly compromised that it doesn't fucking matter if your hypothetical Republicanist alternative tries to reign them in, because in liberal society there is already a massive extent to which popular consensus decides if you live in squalor or not based on what you say. That's what "a reputation" is in liberal society.

The only thing to do is to educate people on what their own interests are. If there is some hypothetical world where people are just determined to vote themselves into hell, then that represents a failed project and a state that must be overthrown.

Some people would consider me intolerant for being against circumcision and piercing of infants' ears, because those are deeply-held cultural traditions for some people.

There is a difference between speaking against something and banning it. This is ultimately just a question about the nature of reactionary religious practices, not "free speech" itself.

Reactionary and hate speech makes me fuckin sick. Yet I'm terrified that attempts to officially ban it just fuel persecution fetishes in people who practice it, and cause them to go further down their rabbit holes and drag more uncertain people with them.

While not as fundamental, this is another common trope among liberals, though I am glad that even radlibs have started to understand that deplatforming is good and works. Yes, the new circumstances fascists are put in give them new tools with which to recruit, but that's the dialectical nature of reality. What matters is not that they have new tools but that those new tools are predicated on them being deprived of old tools that are much, much more powerful, and being able to call yourself a fascist in open society is much more powerful to recruit new fascists than some precious little song and dance about "look at who you aren't allowed to criticize".

I would like to further point out that your likely frames of reference -- either America or states just to its left -- overwhelmingly don't prosecute what you and I would call hate speech, it is the social consensus around some of that hate speech being bad that pushes it to the fringes. It is the banning of it -- which is something that should follow from that social consensus in a democratic government -- that would for most intents and purposes stamp it out.

There's also the matter of social programs and such for the alienated and dispossessed people who it might pick up or who have even already been caught up in it. The law does not need to be punitive, and many fascists are ultimately also a type of victim who the state can help out of their fascism if the state actually wanted to do so.

In some ways yes, but it already happens. The way reactionaries frame the debate (e.g. freedom of expression is the freedom to harass minorities with slurs on campus) is actually a fairly recent project starting in the 90s (perhaps to discredit freedom of expression as a goal). The leftist approach to freedom of expression (e.g. advocating for the people our state is actively bombing, private/personal property, whistleblower attacks, intellectual property etc.) tends to be a lot more nuanced.

I think the idea of the slippery slope is a bit banal. It's not really swaying people one way or another, it's just people will find it as a convenient excuse to "both sides". e.g. Australia banning both Nazi salutes and Hamas flags. This didn't need prior justification to do so, inasmuch as Australia has free speech laws to begin with. If supposedly "free" capitalist states can do such things, why not a socialist state? It makes them only just as bad on that one issue, not worse, which kinda means that if you feel such worry about a future socialist state, you should feel the same worry about current capitalist ones.

To say nothing of how any restriction would be punished. Imprisonment is worse than a fine is worse than rejection from a campus is worse than rejection from a social group. But all societies practice a grading scale of all of those (wrt. speech).

I don't think you're crazy for worrying or even thinking about it. I think it will come down to the circumstances of whatever revolution happens and what groups are involved in negotiating the future. Personally, I'd want to promote active debate both inside and outside the party, but your right to speech is limited from recruiting foreign actors to help overthrow the government and conspiracy to commit crime (depends on the crime). Maybe something about active military movements (should such a thing exist) during a conflict? Even if you're a one party state, you want to have a lot of ears on the ground to address particular grievances, however mundane, and safe discussion is a good place to explore ideas. (this is something that I disagree with right wingers on, if a lot of minorities feel unsafe even if the state isn't coming down on you, you won't get productive discussion, you'll get a circle jerk of the dominant ideology)