Yes you can. Just ask at the front or ring and pre-book one. Often it will be a 4 top that they have removed 2 places from. You can also stipulate (at a 4 top) how you want to sit - across the table, or beside each other. Enjoy your cruise.
I am sure that one of the Round the World bloggers will be happy to answer this for you. It is 5am in Cape town right now so it will be a couple of hours before they start posting.
No need to book. Just show up (same hours as for the MDR) and tell them your cabin number. Sometimes have to show your key card on the first morning. Enjoy.
On Noordam Nov Dec last year. Silent auctions and live auctions took up a large chunk of the bar and seating area. Saw passengers reserving seats for the auction with "reserved" signs.
Supervised RAT tests can be requested at many of the pharmacies in Auckland. There is a 15min wait and then you receive an official report to show at boarding.