First, I think you are going to have only one "dressy" night...the sea day.
Second, Taormina and Kotor are the only tender ports. Any port can be a tender port if there are more ships than docks, but that is fairly rare. (Note the fifth ship at Juneau, for example). Corfu is one place where sometimes there are too many ships.
Third, if you book a private tour, yes, an hour after scheduled arrival should be fine. Remember, if its a truly private tour...just for you and your group...you own the tour. They will wait for you.