The MAX32660-EVKIT# contains an authenticator DS28E05R+. Do I need this in my circuit?
No. The DS28E05 is only needed if you want to support drag-n-drop programming like the mbed site uses. If this will be a development platform and you want to make it mbed enabled, or just want to allow use of the drag-n-drop interface, you should include the DS28E05.