See the following link for the required and optional configuration steps to use digital networking with Unity. Yes, you can restrict the ability of subscribers to exchange messages by limiting the search scope. This is also described in the link below.
Administrative access is controlled by CoS. If a user does not have a subscriber account or an account associated with a subscriber account with a Class of Service that allows access to a particular Unity server, they will not be able to administer that server.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...