The channel manager will close the room on all dates which do not have a valid price available for sending to booking.com. Make sure you have prices for the complete range of dates you are sending (1 year or 2 years)
2) "Room code is not unique " warning when saving in Beds24.
Each Booking.com room ID is unique and can be mapped to only one room in Beds24. If you enter the same Booking.com room ID more than once the room updates will overwrite each other causing inacurate information being sent to Booking.com