>The problem with this is obviously that you then either have to have no moderation at all or it has to be 100% perfect
I'm not sure. You can let the users moderate themselves, then you're still just carrying bits. That's where a pluralistic organisation of the platform comes in handy. Things like Reddit or image boards are not just one community, but a plurality of communities. None of those suit you? Go ahead and open your own subreddit, splitter! Then you can moderate there as you please. The problem is of course, the bit carrier cannot expect an advertiser to agree with all the subcommunities. But that's a different, and solvable problem. You need better targeting for ads and you need to accept that some subcommunities will just not be attractive for any advertisers at all.
It wasn't long ago that it was shown that being host to a hateful sub community lead to overall higher levels of hate in unrelated communities.
You don't actually have this imagined separation you imply: hosting fatpeoplehate mean you impose a higher moderation burden on unrelated communities. And while the reason for this might be the principle of free speech, in practice you are only defending the act of hating fat people.
I'm not sure. You can let the users moderate themselves, then you're still just carrying bits. That's where a pluralistic organisation of the platform comes in handy. Things like Reddit or image boards are not just one community, but a plurality of communities. None of those suit you? Go ahead and open your own subreddit, splitter! Then you can moderate there as you please. The problem is of course, the bit carrier cannot expect an advertiser to agree with all the subcommunities. But that's a different, and solvable problem. You need better targeting for ads and you need to accept that some subcommunities will just not be attractive for any advertisers at all.