Scandinavia 2 weeks must see..hope to do entire trip by boat and train?

Is there a question here?

For two weeks, Stockholm-Copenhagen-Oslo-Bergen or Copenhagen-Stockholm-Oslo-Bergen are popular routes. Or vice versa.

The earlier post is good, but we loved our Norway North Cape cruise. We visited 6 ports in 11 days and the fjords are amazing.

There is a reason the Norway in a Nutshell route between Oslo and Bergen is so popular: The scenery is gorgeous. I've listed the components of the classic NiN itinerary below; the trip can be taken in either the westward or eastward direction. (There are flights into Bergen as well as Oslo.) There are NiN variations, but if you want to see some of Denmark and Sweden as well as Norway in your 2 weeks, you may not have extra time for the Norwegian fjords. The full NiN itinerary can be completed in a day (transfers are extremely simple), but it's a long day, so some people like to break the trip along the way. Although September is not peak season, lodging in the fjord area is limited, so you should find yourself a room before buying transportation tickets for a two-day NiN trip.

• Regular train from Oslo to Myrdal (book at vy.no in combination with the Flamsbana listed below; buying early will usually save you money on the Oslo-Myrdal leg, and sellouts are possible)
• Flamsbana train from Myrdal down to Flam (book at vy.no as a single trip including Oslo-Myrdal)
• Naeroyfjord ferry from Flam to Gudvangen (book at norwaysbest.com)
• Bus (scenic ride) from Gudvangen up to Voss (pay driver, possibly only by tappable credit card)
• Regular train from Voss to Bergen (book at vy.no, but I think this fare doesn't vary)

Both Oslo and Bergen are attractive cities worth some time. I think Stockholm is a place most visitors would appreciate having a bit more time, but sightseeing interests vary. I haven't been to Copenhagen since 1972, so I'll make no suggestion about that city.

The best option to travel the west fjords area is by rental car. There are some official landscape routes.
With NiN and especially by cruise ship you will always travel in a bubble - OK if you like it.

Best travel time is mid June to mid August.

Flåm and Geiranger are over-crowded tourist hotspots. Bergen is a nice town.

Thanks for all the helpful information. One last question: While staying in Bergen, checking into Airbnb's? Is it worth it? Less pricey than hotels and have a kitchen for cooking meals. Would love to hear from folks who have done AirBnb's in Scandinavia.

Bus (scenic ride) from Gudvangen up to Voss (pay driver, possibly only
by tappable credit card)

Or with cash.

Regular train from Voss to Bergen (book at vy.no, but I think this
fare doesn't vary)

Correct, it's a fixed price for the regional trains as far as I know. But, the long distance trains Oslo-Bergen also stop in Voss, and you can use them between Voss and Bergen, but the price for them varies.