Thanks Kim for your timely reply. I was beginning to worry that we had made a bad choice to go on this cruise!
Your message had a great resonance with our reasons for opting for this cruise. We really want to see and discover the islands and from my research, the best way seemed to be by cruising. We have planned shore excursions on every island and have gone with NCL offers. They may be more expensive than ones we could have organised ourselves, but we are not charged with the responsibility of getting back to the ship in time for sailing. To us, this seemed to be a fair guarantee of being able to relax and enjoy the experience.
Our plan was to treat the ship as a floating hotel (just as you mentioned) and we are combining the cruise with 6 days in Vancouver where I am told we can do all the fine dining we would want on a holiday.
I am more excited about this holiday than I have ever been, and this forum has been invaluable in giving us a clue as to what to expect. I will certainly post my findings when we're back.