Simplify the rules!
I think the more detailed you try to make the rules, the more alienating they become. With the best of intentions, it's easy to make something appealing to almost nobody. I prefer very simple, even vague rules and then maybe a separate list of examples of how those rules might apply. The rules don't get to change without votes, but the examples can be tweaked as needed.
I don't think I can explain what I'm talking about without tipping my hand about my views on things, so I guess I'll lean into that.
We see already that people are upset that the "no hate speech" rule, as written, might trip up people intent on reminding everyone as often as possible that they don't approve of transgender people existing in public spaces. And yeah, not to put too fine a point on it, one of the most-defederated servers out there is spinster.xyz, so that seems to be an issue.
The idea of existing online is that other people aren't going to think like we do. That's a good thing! If you don't want to encounter people different from you, then you probably want to build a server that doesn't federate with anyone, like a former US President has.
By way of analogy, if you want to hang out in your living room, you can definitely say whatever you want. If you throw a party in your house, you can probably mostly say whatever you want, although you run a small risk of driving people away. If you visit a party in someone else's house, you should be more careful about what you say, especially if you're the sort of person who says negative things about other people with regularity.
If your freedom to express every opinion is of more value to you than your relationships with "people in general," then you might frequently run into trouble with rules designed to prevent overt offense.
If you believe that your conservative Christian views require you to express opinions that remind others that their safety is endangered by people (not you) who share your conservative religious views, then maybe you should spend some devotional time re-reading John 15:12-25. And maybe "quick to hear, slow to speak, slow to anger" as James 1:19 reminds us.
The UFoI exists in large part because of intolerance from one end of the political spectrum. I think that reshaping the rules to satisfy intolerance from the other end of the political spectrum would be a mistake.
I propose "No hate speech. Don't use pejorative or discriminatory language about any protected characteristic. Remember that you are talking about human beings, and keep that in mind during any disagreement."
Then in the FAQs, you can have "What is a 'protected characteristic' in the context of 'hate speech'?" and mention "In Europe a 'protected characteristic,' in the USA a 'protected class,' and in Canada a 'prohibited ground for discrimination', these include, but are not limited to: age, disability, ethnicity, gender, pregnancy, religion, nationality, sex or sexuality."
As far as examples, and people already trying to push for strict definitions, I think that's a mistake. The Code of Ethics is about the minimum requirement, not a comprehensive list of dos and don'ts. One server might decide that "I'm gonna slap the next member of group X I see" is disallowed, while another might not. We don't want a monoculture, so we shouldn't codify one.
And yes, this is ultimately just kicking the can down the road a bit, since I feel certain that once we launch, "rules lawyers" will quickly find a post on another UFoI member server they don't like, report it, and demand resolution. But at least then there will be a concrete example in hand, and due process will apply. Now it's just who is noisiest pre-launch while talking about hypotheticals, which seems less than ideal.