I'm considering buying, and would like to know if there is a way to prevent admins from being able to read all private messages, or to notify a user when their private messages have been read by an admin. I have several admins, and would like to limit their access.
The only way anyone could read users PMs is if they have direct access to the database, or they login as that user and read the messages. There is no notification feature either way.
P.S. IMO if you do not trust your Admins, then they shouldn'ty be Admins. That's just my opinion.
If they have direct access to the database, they can do absolutely anything to your forums. It's extremely dangerous to have another administrator, and suicidal to grant anybody database access.
All IP addresses, including guests, are viewable to administrators. They can be viewable to moderators and all other users as well, depending on your preferences.