Read private messages
As administrator can I read conversation members have between each other? I say this as I was thinking of having a "tender" section on the forum where users can request quotes for services. Instead of people replying to the thread with prices etc, they are invited to just send a private message to the user with their quote. However I would want to keep an eye on this to check services providers aren't slagging other suppliers off and doing anything too pushy to get the job.
Allow a user access to just 1 thread
Also I might invite a company to see a thread I think they can contribute to. Eg someone talking about insurance, then invite an insurance broker / expert to comment on the post. But I don't want them to see anything else on the forum.