What would really complete a site like this would be a wiki or collaborative style document editing platform where family historians can construct a story of the family history in booklet form. Each document should be editable by all family members and can link to family member profiles when referenced.
For example, if I wanted to write a biography of a famiy member, it should be in a section called biographies and then if someone later wants to put together a book and include that biography, they should be able to simply reference that biography in a tag or something and it gets pulled into their family history book. If a photo is needed, it should be able to be referenced from the family photo album and inserted wsywig style.
I was really thinking of something like how wikipedia is set up except oriented at family and individual documentation.
I have the full vision for this in my head and was considering just authoring the website myself but I want to give you guys a crack at it first because I don't want to reinvent the wheel.
We currently offer fact, events and biography editing only by certain allowed people in the tree - usually the site managers. This ensures that only selected few will have this privileges of actually making changes in order to not make a mess or to hold individuals from doing un-wanted changes by the owner.
And in order to allow individuals to edit the tree, it needs to be on the web site (not edited and published in the Family Tree Builder) and you will need to add the privileges to the users in your settings.
You're making good points for us to work with - referring to people on trees along with events is very important and we will take this as feedback. Also, we would be glad if you could point out what is currently different and wrong in our documentation system (such as the biography) that needs improving in more details (What are the points that are critical and different from Wiki pages that could enhance your experience)