Overall, I agree with your assessment, however I'd rank the food and food service in the Caravelle a little bit higher. The ship is old and worn and needs either a total refurbishment or retirement. Things wear out eventually.
We noticed the smell aft and thought it was the deisel (or propane?) exhaust from the engines that come out that big smokestack above the spa. It was a lot more noticeable when we were at sea rather than in port and the engines were firing away.
We didn't have any problems with vibrations, but we were about midship on the Atlantic deck. You could still tell we were moving and the engines were running. As our only cruises so far have been on the Zenith (but scheduled this fall on the Mercury and next spring on the Infinity) we have little to compare to.
Also - on your departure, New York was very high-stress when we sailed to Bermuda on our first cruise but Jacksonville (for the Southern Caribbean) was like the difference between day and night. Jacksonville is a new facility - beautiful and runs like a top. Very quick checkin and also debarkation at the end of the cruise. I think this is more up to the port they are using and less under control of the cruise line. We were delayed on disembarking in NY after returning from Bermuda for more than 3 hours waiting for the port authority to clear the ship, not Celebrity's fault.