I think a lot of groups would find it handy to be able to establish a "Template" or "Default" for the collection of options on the Membership page for new members. That is, when a new member joins their "Membership" is initialized from the template (or default).
That would include their "Email Delivery" and "Posting Privileges" currently, plus whatever new options are implemented later. Notably, this would supersede the "New Users Moderated" checkbox on the Settings page; new members could be set to any Posting Privilege.
I don't think Role ought to be part of the template; but I'm not entirely sure why not.
Likewise, there would be a template for new moderators, and new owners, each of which applies when a member's role is changed to one of those two (but demoting someone back to Member should not reset the member's options to the Member template). The "Owner" template would include the "Notifications" and "Owner Email" options; the "Moderator" template would have those plus the "Moderator Permissions".
My original thought was that the list of those three templates (member, moderator, owner) would be accessed a "Templates" tab on the Members page, next to the "Members", "Moderators", "Pending Approval" and "Banned" lists. But I could see an argument that they should be accessed from the Settings page instead.