I am an independent advisor investigating this inquiry.
1) You can not remove the No Staff column from the Bookings calendar by design. This functionality is a safeguard when a staff member is not assigned. As a workaround, you can change the Day calendar view to the Week or Month view.
However, based on others feedback, users are asking for the easier capabilities to add and remove administrators, as well as distinguish between an administrator and scheduler. So, I encourage you to influence change by adding your requirement to the Microsoft Booking feedback portal.
If you find this information helpful, please mark it as the best answer or like it, which will assist others with the same questions.