I think the existing moderation systems are great as they are to deal with any kind of content- OT, flames, trolls, swear words are all capably dealt with by the community without the need to have any additional guidelines.
If you find a node personally offensive then downvote it and message the author letting them know why you downvoted them. If you feel a node is offensive enough to be of damage to the community (and not just your own sensibilities) then do the same and consider it.
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Life is a tale told by an idiot -- full of sound and fury, signifying nothing. William Shakespeare, Macbeth