Minor Description
Several thoughts come to mind:
The "Edit" button doesn't really reflect the reality of what you do; there, you add users to a pool, or change their roles.
The roles are ambiguous. You can select, e.g. Read or Write. Intuition causes me to look for "Both", even though deeper reflection suggests that you could not write without Read.
"Name" seems ambiguous. Behavior fully disambiguates that: if you type in Joe Sixpack, the form turns red. If you just type in joe, the form is happy. Profiles refer to that as "Nickname"