If the forum is not moderated why would someone else be allowed to edit posts besides their own or admin?  Why would someone be allowed to pin a post besides an admin in one of these forums?  Those users who are Tab admin or site admin can edit posts even in a non moderated forum.  Same goes w/ making one sticky.  This will not change.  I have used several php based forum solutions and they all follow these same type of guidelines from what I have seen.

Hi, I reply here as I need this feature too. It's needed in my case in a community situation. We do have volunteers who every now and then help remove inappropriate messages or to manage the threads by highlighting some and or stop a thread and redirect to another and so forth. They can't manage the entire forum, but are to be "moderators" in a group or a forum within a group as they are the knowledge members scanning through the threads every now and then.

 Hope that clarifies a need.

Cheers,
/Rob