Pen I envy you the experience that is coming your way. I am back, not yet a month, and, several times a day, my mind goes back to all the beautiful places and experiences I had.
I was a 1st timer as well, and, finally had my chance to see in person, places I have watched on tv for so long. It may sound very hokey, but for me, these places/sites moved me, more than I can say.
For my itinerary, Rome Florence,and Sicily had the farthest rides from the ports. We were in Florence on a Sunday, so our ride was shorter, bit would have taken a bit over 2 hrs. The ride from Sicily to Taormina was a testement to the bus drivers training, because screams were heard
If you can do private tours, I would say go for at. Less walking from the drop off point to the sights,and personal tours. Ships tours worked out well for us. The one private tour we had booked in Monte Carlo, was canceled due to rough seas.
Enjhoy every second of planning, that's half the fun.