Dan-
If the documentation used a "Help:" namespace, then none of the links would have to be updated, and all an administrator of a new site would need to do would be to download the documentation database dump and upload it.
Yes, a Help: namespace would probably make sense. Compare:
Help:Edit conflicts Wikipedia:Edit conflicts Help:Editing Wikipedia:Editing help Help:Sections Wikipedia:Sections
Besides, our own spin-off projects have the exact same problems as Memory Alpha when it comes to these help texts.
Offering this for download would be very easy if it contains no self- references and is nicely isolated. For bonus points, write a script that automatically fetches and installs the latest version of the help texts (preserving older versions and warning if they exist).
What to do with "Help talk:"? Should they point to the Meta talk pages?
If everyone agrees, I can set up the Help: namespace on meta, and you people can try to come up with a site-independent structure and contents for it. All that needs to be done then is add the Help: namespace to the default, export it into a tarball regularly, and optionally, provide the aforementioned import script.
Regarding translations, since Meta is supposed to be multilingual, we'll just have to set up separate namespaces for each language there, e.g. Hilfe:, Aide: etc.
As for the policies, this would be the kind of stuff I'd like to see in a web-based installation script (phpBB like), where you then could just select some key policies
[ ] NPOV [ ] Naming conventions [ ] Fiction
And the script would automatically import these into the $wgSiteName namespace. Yeah, I'm dreaming, I know.
Regards,
Erik