Ultimately, though, the solutions are going to have to mostly involve the community. We'll probably be posting about this more in the coming days.
1. Click over to whatever textbox allows you to edit the site guidelines.
2. Clarify the "what's on topic" clause.
3. Add a "criticisms must be constructive", perhaps deriving it from Paul Graham's "colleagues working together to uncover the truth" wording from the Pending Comments announcement.
Start by spelling out the norms you want to see here, and we can all work to move the site in that direction without having to nail down the statutory language or figure out what 100 lines of lisp will best implement them.
Hmm, seems like I'm being all talk. I'll just put my demo online, within the next couple weeks.
Wikipedia's problem-solving mechanisms are impressive and effective for a project with a single coherent goal, but they aren't good at fostering community. In fact, they do the opposite thing: they artificially factionalize the community, which holds together despite and not because of those mechanisms.
"Don't be a dick" covers most of it. "Don't attack the person making a point. And don't be vicious when you attack their point; test it, probe it; destroy it; just don't be vicious".
Sadly having extensive documentation about what is or is not allowed leads to destructive bike shedding and comcern trolling.
Adding the small extra details of "Don't attack the person making a point" and "don't be vicious" would be improvements on the current guidelines.
Also, for example, adding "sarcasm is not helpful".
I agree with Thomas(!), clarification of the guidelines would go a long way.
There are certain topics that bring out the flamewars more than others, and those should get particular attention. Most things political, sexism, nutrition (weird but true), and so on. Most of all I think it's important to reinforce the idea that you can disagree with someone even on deeply held beliefs and still be civil about it. Moral certitude does not make it ok to be mean.
To avoid Wiki-style lawyering (as noted in other comments), I think the guidelines could really be kept incredibly small. I think pg's "colleagues working together to uncover the truth" line covers 90% of what HN discussions should be.
I'd also add "no comments that don't add information/low signal comments", to avoid "+1" style comments and humour. I'm not sure most of the community agrees with me, but I don't like such comments here. Reddit optimises for fun being on Reddit and reading comments, HN optimises for getting the most on-topic information in the least time.
It'd be great if a tiny set of guidelines were enough for HN, but that's very optimistic about people being able to pick up on implicit rules & values. A well-written set of reasonably detailed guidelines would make explicit what the majority of decent HN commenters already agree that HN should be.
FWIW I was slow banned years ago and it still hasn't been removed.
It may just have been a moderator having a bad day, but the message when it's left there is clearly "You're not welcome here.". That's a message you might not want to be sending to people who are saying what you can't say.
(note that this is the standard pep talk that has to be delivered to moderators everywhere from time to time, and indeed that my friends periodically deliver to me when I'm worrying the same way you are :)
If you fix the Font Stack in news.css so that it is
font-family: sans-serif;
font-family: verdana, sans-serif;
Good Luck with the new role.