Judy... hope this helps! I was with my mom, so my answers reflect that experience.
l. What time can you actually board the ship? While we have done many cruises, Europe and elsewhere, never on Crystal. We like to board as early as possible, and have found the "boarding time" on other lines not accurate, ie. you can actually get on earlier.
Boarding time was listed as 3:00. We boarded at 1:30 and there were already people on board. There was someone just inside the entry taking handluggage so you didn't have to drag it around the ship with you. They told us at embarkation that the cabins would be open at 2:30, once on board they told us 2:00. We went straight to our cabin and it was ready.
2. "Hot" is relative. I just flew in to Michigan from our other home in South Carolina. It is routinely 90 plus lots of humidity, with heat indexes always in the 90's or even higher at this time of year. Your definition of the Mediterreanean being "hot."
You should be right at home with this kind of heat in SC. The hottest day we had was in Debrovnik. Even the local tourism person on board to give information told us it was expected to be the hottest day of the year there. She said, "Do NOT walk the wall today." If the locals think it's hot, it's hot.
All of the days were bright, sunny, hot and humid. You instinctively looked for shade whenever possible.
3. Dress for women: Formal vs. Informal. Is there a great difference, what did you wear and find other women wearing?
Overall, I find Crystal to be dressier in general. I didn't see very many women in typical "Carribean vacation attire" (shorts/t-shirt/sneakers) unless they were exercising. I think you'll find that it's a virtual fashion show regardless of the time of day. We saw some real get-ups going ashore. Women in full make-up, hats, high heels. My mom and I wore capris, flat sandals or Keds and a short sleeved top. You'll need to have your knees and shoulders covered if you plan to enter churches, etc.
As for the dining room... I don't think some of the women knew what "casual" meant. Many we saw were quite dressed up all the time. The first formal night was the dressiest, the 2nd one was next and the last one was the least dressy. We went to Prego on the second one so we only brought two formal outfits and wore one to Prego and one to the dining room. We saw long gowns, cocktail dresses, simple "little black dresses" and a few dressy pant outfits. I don't think you could be too dressed up on this ship. I looked at the men as well, to see if they were wearing tuxes and I had to look to find a man NOT wearing one. Lots of white jacket tuxes.
4. Any port trip you would recommend? I rather prefer setting up my own, but this time I have not except for finding a private guide in Rome.
We didn't do any shore excursions. My mom is older and tires easily. We usually spent 2 hours or so wandering the port and then went back to the ship. I can tell you, though, that we heard many people say that the ship's excursions were LONG and tiring. One lady described it as a "long bus ride, followed by walk here and look, walk there and look, walk some more and look some more then get back on the bus and ride some more."
5. I have read some reviews of the dining experience-----many of them nothing to rave about, comments about the waiters dropping dishes, and the dining room being very very noisy. ????
We found the dining room a little bit noisy. Not bad, though. And no dropped dishes! As for the food, it was a bit of a disappointment. It looked delicious but lacked flavor many times. The presentation seemed to be the focus in preparation. We tried Prego and didn't think it came close to Prego on Harmony. The atmosphere is lacking even though it is beautiful. It's too close or something. We felt like we were part of every table in the room because you could easily follow everyone's conversation. Silk Roads got rave reviews but I learned that I don't like Japanese food. If you do, you'll love it there. I heard one woman claim to have gotten her cruise fare back at the sushi bar! Our favorite place to eat was the Trident Grill. Be sure to stop by the ice cream bar and say hello to Noli! The ice cream is very (very) good. We went to the Lido Cafe or the Bistro for breakfast. Both are good. We didn't go to the dining room for breakfast or lunch. The service is incredible in all areas of food service. However, be prepared for room service to take up to an hour in the middle of the afternoon when your steward/stewardess is off duty.
6. How did you find the Fitness Center??
I did not attend any of the classes or use the equipment but I walked through there several times. They have a small fridge filled with bottled water. I would go there and get two for going ashore. The bottled water in the cabin was the really big bottles. You can also get the smaller bottles in the Lido Cafe. Just ask any waiter and he will bring it to you. We did this twice during breakfast to have them later. The gym is quite small, though. Plan to go at "off" times would be my suggestion. Many people chose to walk the Promenade deck. If you like to walk, check out Debbie Rocker's Walk On Water (WOW) program. There is also a cruise long walkathon. Record your laps in the notebook on the stern of deck 7. At the end of the week they total them and give out prizes. I came in 2nd with 103 laps (31 miles) and got a Crystal hat as my prize. Lots of people walked more than I did, but they didn't bother to record their laps. My goal was to walk 20 miles in 10 days so I made sure to keep track.
Have fun on your cruise!!!