I did the 11-day "round voyage" on Havila last month and enjoyed it very much. I suggest that you sign up for some of the excursions on shore, like Nordkapp and Trondheim. Some of the others take you from one port to another one along the route, which can be a good way to get inland and see more than just coastal scenery. I got into the Geirangerfjord but I think you'll be in another one nearby because it's later in the season. You'll also have a much better chance than I did of seeing the Northern Lights. PM me if you want more detail about the ship and voyage.
Bergen is a lovely city and you'll find plenty to see and do in the time you have. I recommend the walking tour offered by the Bryggen Museum, and the museum itself. I'd also recommend Haakon Hall (not so much the Rosenkrantz Tower) and St. Mary's Church. Be prepared for rain, I was lucky but it will be wetter in October.
Generally this looks like a good plan, with some excellent cities and enough time in each to get a good feel for them, though not in-depth exploration. Your city visits will be fast-paced but the voyage will be relaxing and super-scenic. I don't know whether you're looking at flights yet, but you'll probably do well with SAS, Delta, or Icelandair. You're smart to be flying "open jaw" into one city and home from another. Have fun planning this trip. This forum generally works best with more specific questions. I doubt if anyone will have anything negative to say about your general plan as you've outlined it.
