Sorry for newbie questions. Apologize if the questions do not belong to the promo thread but I dont seem to be able to find a proper thread to ask the questions.

When you book the hotel online, you guarantee it with your CC. In this case the Marriott Visa.

But you want to pay the bill with either Marriott GC or TC. Do you do it at check out or do it the night before?

Because many hotels would slip the bill underneath your door whenever you already have a CC on file. Assuming they have already attached the CC to the room, how difficult for them to back it out and put the charge to the GC / TC?

Also can the property put a partial bill on a GC / TC where the balance on the card is not enough for the whole bill, but the FD can put an exact amount on said GC / TC so to wipe out the balance on the GC / TC?