The reader has no power as they have no buy in - the "user" a little power to post/comment from account. The "producer" should likely be promoted to "mod" as soon as they are trusted.
The "mod" have as much power as possible without endangering the instance.
The "admin" have strong power BUT a VERY strong social rule not to use it. The running of the instance is in the hands of the "mod/producer"
Actions are socially mediated by the #4opens with audit logs to bring transparency.
To support this server and the OMN project https://opencollective.com/open-media-network