Janbee, your post has been here for over a week now and nobody has responded. That is not an unexpected result. There are only a dozen or so of us who routinely read and respond to messages posted on this forum. I suspect that a lot of others read but do not respond.
I do not have the answer to any of your questions, but I wanted you to know that your post has been read. I took the cruise in July 2006 and had a great time. My only advice is don't make the mistake made by one of our fellow cruisers concerning packing for the trip. He researched the climatology of the area and concluded that he needed only clothing for cool to cold weather conditions. To make a long story shorter, we encountered an epic heat wave during our cruise. Long-term weather trends can give you a rough idea, but you're almost certain to be fooled at least part of the time. As with almost any vacation trip, the key word for packing is "layers".
Not only do I not know anything about acccommodations in Amsterdam, we were 24 hours late getting to the ship when we took the cruise. Severe weather in the Washington, DC area delayed our flight for one whole day. We got to the ship about six hours before it departed Amsterdam. GCT had already made tentative arrangements to get us to Cologne to meet the ship there if we had missed the sailing.
It's a great trip. Go and have a marvelous time. "Don't set your expectations too high and you're almost certain to be pleasantly surprised."