User gallery size
 

I am looking to add gallery space for paid members.

Is there a way to set the total server space an individual user can utilize for their galleries? Can this be set at a user group level?

Can the software be set so that under a common "supporting members Gallery", each user would have a sub-gallary auto created either when they post their first picture, or when they are moved to the supporting member usergroup? And that they would only be able to post pictures to their specific gallery?

Members of usergroups can be limited to total server space by using Maximum File Size and Maximum File Limit via the Usergroup Manager (screenshot), member folders can be created by using Is Members' Folder via the Category Manager (screenshot, example), and access to categories can be set on a usergroup basis via the Category Permissions (screenshot).