Last question first: Administrator isn't a role, per se (it's a way of life). It is assigned in a different way and you can't copy it. You either are or you aren't. It is assigned in Site Administration->Users->Permissions-> Site administrators (rather than assign system roles).
First question: It is all about permissions. I'm still on 2.8, so the permissions may vary slightly (they haven't changed a lot since about 2.3 as far as I can tell, but they could have changed a little. There are a lot of permissions. Sometimes you have to experiment a bit (I like to keep two browsers open...one logged in as Admin to mess with the role and one logged in as the role I'm fiddling with). Some permissions only work when another is allowed...or when a role is at a particular level (I want my trainers to be able to move their courses...but that is a permission which only works at the site level, which means either they can move any course or they can't move any course...I can't change where they can move them...scary!).
- You probably want to remove permission to view others' grades, view course reports, overview reports (okay, all Grades reports), view course logs, view activity reports, view activity completion reports, allowing grading in any activity (there are a bunch), allowing deleting of attempts of any type in any activity.
- You probably want to allow permission to configure enrollment instances (maybe), view participants (you have to see them to add them in the course), assign roles to users.
There may be more...Maybe take a look at non-editing teacher...it might be closer to what you're looking for.