You have to be careful; if you browse at 5 you'll get a venerable circlejerk. +3 or +4 seem much better (if you set up a negative funny modifier) for getting worthwhile discussion that also has dissenting opinion.
Fark's style of moderation is more about control than actually taking care of jerks. IMO, if there are going to be specified moderators their only job should be to get rid of the outright spam and nefarious links (to malware sites etc.) I help moderate a 4chan offshoot, and my job as moderator has three parts:
1) Get rid of spam/illegal content (namely child porn)
2) Get rid of content that is not relevant to a board (posting about fighting games on a train discussion board, for instance)
3) Get rid of spammy trolls, the ones who will hop thread to thread posting irrelevant opinions or otherwise trying to derail every thread
That last part is censorship, yes, but is only done when something or someone seems to quickly fouling the entire community. I try to use it as rarely as possible; an IP or tripcode has to show a history of such antics before it's even considered.