I want to give an honest answer without appearing too flipant. You can do all those ports on your own, with cruise ships tours, or private tours. The decision really depends on your "travel smarts" (ability to do your own thing), budget, and personal preferences. For example, we just returned from an 8 week trip (including South American, Africa and Europe) and did not take a single tour (this trip included two cruises). Most others would have used many tours. I will give you a quick start. The easiest place to do totally on your own is Gibralter. Barcelona is also pretty easy to do without a tour. The other ports are very dependent on what you want to see, so please give us a few hints and we can help.
I will give a slightly different point of view while acknowledging the wisdom of the previous post. 2 years ago we easily did Casablanca on our own and simply walked the 1 1/2 miles from the ship over to the Hassan II Mosque, took the amazing tour inside the Mosque (generally not included on cruise ship tours), and than walked into the central part of town, had a drink at the Hyatt and than shopped in the bazaar (across the street). It was a great day. Three weeks ago we were again in Casablanca, and this time we took the train to Rabat, explored that capital city, came back to Casablanca (the train is a 1 hour ride) and spent some time in the bazaar before returning to the ship. My only point is that this place can be done on your own if you are somewhat adventuress. The most impressive part of Casablanca is the Hassan II Mosque, and we continue to be amazed that most of the cruise lines do not arrange for the inside tour. The Mosque is very new, the 2nd largest in the world, and the inside is absolutely amazing (they can handle more than 30,000 for prayers. There are also many taxis available in Casablanca, but you always need to negotiate prices before you get in those cabs.
We've had a lot of discussion about tours lately. Some got a bit contentious unfortunately - and I helped it get to that point, sad to say.
I remember my Navy years which included lots of time in the Med. We'd always do it on our own, wandering around and perhaps getting a taxi to take us to someplace. I recall doing this in Italy, Majorca, Monaco, Greece, Israel, even Egypt. Of course, safety is a different issue for a group of young physically fit men than it is for others.
As Hank says - it depends on your travel savvy in most places. Bad things can happen regardless of who you book a tour with. If you are comfortable with the port-of-call, then do what you feel is right. New place? Perhaps a ship's tour is the better choice. But only you can decide.
To answer your question, Hank, we are pretty adventurous.....we have travelled in Europe a bit (not on a cruise though) and always do it on our own. We generally take a tour the first day we arrive in a new place but then do everything on our own after that.
My concern here was the limited amount of time we have in each port. Generally, we have the luxury of several days to explore a city so I was trying to maximize my time.
I seem to be getting a handle on things now. My plan for Casablanca is almost identical to your first trip there. We are going to do our own thing in Lisbon, Barcelona, Vigo, do a private tour with driver to Tuscany from Livorno and a private tour to Monte Carlo/Monaco/Eze from Cannes. We will be in Le Havre on June 6th and not sure if that is a good thing or not.Not sure how crowded it will be or what is planned for that day. We have recently visited Normandy, Honfleur and surrounding areas, so may head to Rouen which we have not seen. We can do that by train or may rent a car.
We only just booked the cruise 2 weeks ago and I was feeling a bit overwhelmed trying to plan the excursions at such a late date.
Sorry this is so long....thanks again to all for the great advice!