Oceania Insignia May 31, 2009/Carnival Splendor March 31, 20

My husband and I are going on the Splendor for 5 days to Mexico the end of March. Our 3 grown children are going with us (their Xmas present). Has anyone been on this cruise before?
We’re also going on Oceania the end of May from Rome to Istanbul. I’d prefer to do private shore excursions. If anyone has any info, I’d really appreciate it. Our ports will be:
Rome, Monte Carlo, Florence/Pisa, Olbia/Porto Cervo, Amalfi/Positano, Athens, Delos, Mykonos, Santorini, Rhodes, Kusadasi, Istanbul. Also, if you know of some of these ports where it would be easy to just go off on our own, I’d appeciate knowing that, as well.