Thinking it might be a good idea to control access to journal visibility options like "Everyone" to one or more specific DNN role(s).

Think so. I also raised with Will the possibility of 'over-riding' third party module security settings, given that a couple at least don't implement an interface to control this on their end.

That's a good idea too. Perhaps handled at the API interface in the Control Panel. I was thinking more along the lines of controlling access to the journal security options through DNN roles.

Registered Users could have Private and Friends
Verified Members all previous plus Groups
Super Duper Member could have all previous plus Everyone and Community

Basically some way to control who see's these options on a role level.

Yeah, agree. I was just seeing some relation between the two :-)