You can but many men opt for a normal day suit and tie .
Yes you can and a dress for the lady.
According to the Princess Cruises Answer Book (which you will receive prior to departure), they recommend that you place your order in good time with a company called Cruiseline Formal Wear. Orders can be placed on their website www.cruiselineformal.com. Hope this helps.
Yes you can hire a tux on board princess ships but you cant beat having your own thats if your going to be a regular cruiser and they can press it for you b4 formal nights .