My ships were smaller than lots of the ones who sail this area (70,000 tons or smaller). Of the list of ports you noted, we've been to all of them, and we tendered into Mykonos only. We docked in all the other ports, but if you are on a large ship or if the ship can't get berth space on your date, you may tender into others. I suggest checking with your travel agent and cruise line. I think in Civitavecchia you will definitely dock because it's a huge port, and I've never seen anyone tender there.
The port for Nice in Villafrance definitely uses tenders. There is excellent rail and bus transportation into Nice and Cannes. Do not take a tour unless you want to see the magnificant St. Paul de Vence(walled art colony). Do not waste time and money at Monte Carlo casino which is dead during the day. No tenders in Barcelona nor Naples as they deep water ports.
tendering in Barcelona, Nice, Civitavecchia, Mykonos, Crete, Naples?
depending on what ship you're on and depending on the traffic of how many ships are in port. On the Millennium we tendered in Villifranche (gateway to Nice), and that's it out of your list! We pulled up to dock in Barcelona. Civitavecchia was docked. Mykonos was docked and Naples we docked in aswell! Never been to Crete, enjoy, it's fun!!