Wiki - The paradox of tolerance states that if a society is tolerant without limit, its ability to be tolerant is eventually ceased or destroyed by the intolerant. Karl Popper described it as the seemingly self-contradictory idea that in order to maintain a tolerant society, the society must retain the right to be intolerant of intolerance.
No, impartiality is the removal of the emotional response and personal bias, you practiced impartiality earlier, and it is key to objectivity.
Objective harm can only exist if an impartial outside observer determines that you are being harmed, this idea is the core of the legal system, which I think is also a good analogy for where I’m losing you. The legal system deals purely in ‘objective truth’; what can be proven, is, and the limitation of this system is that available evidence is not always aligned with ‘universal truth’.
I think that the point where I’m losing you is that you don’t believe we can develop enough of a nuanced understanding to make the determinations necessary to align the two, and for some things you are most certainly correct, that’s called the grey area, the indeterminable, the land of fuzzy logic and educated best guesstimates.
But that ignores all the things we can objectively determine to be censor worthy; harm that people engage in regularly.
This comes back to why I said bigotry is self harm. A bigot is not harmed by an outside source, not harmed by anyone other than their own perceptions. A bigot still feels hate and anguish and suffering due to incorrect perceptions that are backed up by the consensus of other bigots, but are not backed up by objective reality.
Societies tolerance of bigots starts and ends at their own actions. Wanting to harm co-operation is objectively harming the constructual foundation of society, and harmful to the disenfranchised, and objectively morally incorrect and can be censored should enough of society wish to. But that begins a separate discussion on social consciousness and social obligations and their related morality.