I'm confused - tightly focused groups with high entry requirements may be able to get away with less moderation, but how would you create something more general-purpose, like HN?
I think the question isn't general-purpose but "what is the purpose?"
If the purpose is collective economic advancement through developing awesome software, all you have to do is support new members of the community in getting going.
If the purpose is having fun, spirited debates, then this becomes harder. However the same rules apply. These are:
1) Stratify the community so not everyone has an equal voice in everything.
2) Every strata has an obligation to help every other strata stay civil and grow the community and norms together.
