I will try to read through it tomorrow. Maybe we should get some more people to check for technical accuracy and just unclear parts.
I would not add any navigational elements to the pages because it's not always easy to work with that. Inserting new pages is difficult because references tend to break and stuff. Most users do search for a specific information thus an additional navigation would not work for them either.
On the missing authentication mechanisms: I think that's an opportunity to invite people who actually use this and ask them to write those pages. I am sure, you can find some help on the forum.
As mentioned above, give me some time to read through it. It looks quite good and well researched. Maybe I can make some supplements. :D
Michael