Ok, i been playing with spaces and from what i can see, author creates a space and invites members. After author creates a space and sets privacy to secret, no one else can view what is discussed in the "space correct?"
Well, not sure about the biography. The nice example of the "Space" can be directories and fields - every directory may have the own sub-directories and the files there. So you may apply this structure as you want. Yes, you may setup your space as closed for non-spaced members.
