Bookings - Prevent the client from booking more than once, a certain period of time

I am trying to use booking to meet with all the staff for 15 mins every week.

Ex : with 52 staff that would be be 52 weeks a year.

Is there a way for booking not to allow a staff member to book, a slot, if they have already booked a slot.  We are using office 365 credentials to validate the employee. So can booking track an existing booking and let the employee know, a booking exists.

Also, if booking is using OFFICE 365 to validate, then can the Name and Email id of customer be eliminated from the "Add your details section"