Reading the posts here, I think 3 levels would be a happy middle ground. These are examples and not binding in any way.
Level 1: Guest: Only able to access unlocked containers, doors, and buttons.
Level 2: Builder: Able to build anything but not break anything placed by others (exception: can farm) and can only access chests locketted in their name.
Level 3: Worker: Level of trust now granted.

 

pretty neat idea, support.