Hi, I'm new to Plex. I've been checking it out on the free side but I'm starting to seriously think about getting a plex pass. My question how far does the pass go?
Plex pass does currently mainly enable additional server abilities.
Does it apply to anybody connected to 1 server?
As far as server abilities are concerned, yes. All users who can acccess a server will profit from the additional features of the Plex Pass.
Anybody connected to a server on my account? (at the moment I have 1 but having 2 at a future date is a possibility)
You can have 'Plex Friends' which are for users outside your immediate family (up to 100).
You can also have up to 14 additional members in your 'Plex Home', among which you can switch in Plex clients very fast (useful for plex clients which are used by several family members). Members of your Home also benefit from the free availability of 'paid' Plex apps.
Any device logged into my account?
Any device logged into an account in "My Home"?
This is the same. There is no difference. If you are the server admin, you are also the master of the Plex Home.
I'd like to in the future use multiple accounts to manage who can delete vs who can watch different levels of content (parental controls).
This is exactly like it's done in Plex.
You can restrict both 'friends' and 'managed users' in the same way:
Assume I have multiple servers and users who can access my account in the home group and possibly the friends group. Some users may connect to other servers outside the home group. Where does the pass benefits kick in?
The Plex pass doesn't add or change anything in this regard.
You can setup several servers in your plex account.
(When members of your family also need to access Plex servers which are run by other people, they need a full plex account. A 'managed user' cannot be invited to other people's Plex servers.
But you can always invite a regular plex account into your Plex Home, so all the Plex Pass benefits apply.)