I think you've missed the point a little here. Content is nothing unless the public can see it. Can read it, and can find it easily.
Top priority is the documentation.
All else is secondary. I do a lot of theatre work, teching mainly. The same can be seen everywhere. Every link in a chain is important, not just the ones with the spot light on them. Authors are welcome to help, but if you start imposing rules on what else they have to do, then I feel you're likely to get less authors, which wouldn't be the desired effect.