You can allow deposits to CONFIRM a booking, separately for members and guests.
Use Site Config, filter varname on PERCENT. You will see the percentage amounts for members and guests respectively.
To turn off deposits, set the percentage to 100. All deposit functionality disappears from member and admin screens.
If you move from deposits to no-deposits, be sure to resolve all deposit-only-paid bookings first. Once you turn off deposits you can’t discover which bookings were in this stage – except by turning deposits back on, and the information about each booking will be shown.
Note that you can list all bookings that are deposit-only-paid using this filter on Manage Bookings:
Note that the above filter is only relevant to CONFIRMED bookings, so you should filter on that one status value at the same time.