I've got haphazard net access this week, so my apologies for this being a partial reply. I'll be posting on remaining issues in a separate follow-up.
With regard to licenses, you generally want them to stay out of the way, and make it easy to get your job done. Therefore I like to take a very pragmatic approach to them. I'm also going to optimise for the inclusion of wiki text into Onlink and other products.
So, let's pretend that someone writes some excellent text you want to include in Onlink. I understand that Onlink is closed source, which is a requirement on the original Uplink source code. A CC-BY-ShareAlike license could potentially prevent the use of wiki text in Onlink, because Onlink itself is not under a CC-ShareAlike or similar license. The license gets in the way. That sucks.
If you want a CC license, then I'd be inclined to use a CC-BY (Attribution) or CC-BY-NC (Attribution/Non-commercial),
with a clarification that linking to the wiki is considered sufficient attribution. This means you can just list "The Onlink wiki" (with a URL) in your credits and be done with it, rather than having to try and list a million billion different contributors.
One potential gotcha here is that wiki users could infer that your own contributions are available under a CC license. You may be happy with all your protected pages being copied to other sites under CC, but you may not. In that case, your license is getting in the way again. In this case, I like Tycho's license more, although I change the working just a little, perhaps to:
Quote:
By posting contributions to this site, you automatically grant, and you represent and warrant that you have the right to grant, to Ferrous Moon an irrevocable, perpetual, non-exclusive, transferable, fully paid, worldwide licence (with the right to sublicence) to use, copy, publicly perform, publicly display, reformat, translate, excerpt (in whole or in part) and distribute such contributions for any purpose, to prepare derivative works of, or incorporate into other works, and to grant and authorise sublicences of the foregoing.
That means others can't copy your work, but you have full rights over theirs. That license stays out of your way as much as it possibly can. The downside is that you may reduce the number of contributions which can be made to the wiki, particularly if people wish to contribute Creative Commons images, or contributors would like to receive attribution for their work. You can also hamper people creating their own guides and handbooks based upon the wiki, and often these can be great for community building.
Finally, if contributions to Onlink require a particular license, then using that license may be best of all. This is a common thing to see in the Perl world, where modules, wikis, and other projects are generally made "under the same license as Perl itself".
Some projects take a "contributions are under license X, except on pages marked Y, where contributions are under license Z" approach. That gives you the best of both worlds, although with the downside of increased complexity.
Please note that I am not a lawyer, and this should not be considered legal advice. If I suggest a license or idea and it's broken, you get to keep both pieces.
All the best,
Paul