Norway in May/June 2019

In general is Norway at that date a really good decision. You will limit your own possibilities by deciding to use public transport only. No critique, just opinion and own experience. Based on that decision doing an own NiN sounds reasonable.

As you are not a fan of "just" good museums I would reduce Oslo to 1 day HoHo bus tour plus little sightseeing. Bergen can be 1-2 days - it is a real nice town. The rest of time I would spend the landscape and you decided for Fjord Norway which is scenic - especially at that time.

For sure worth a trip form Flam are:
- Stegastein: https://www.mark-koenig.de/norway-places-stegastein-fjord-viewpoint/
- Naeroyfjord boat tour aound noon will allow nice impressions: https://goo.gl/maps/kVTayMnnqm92

In Alesund I recommend to get a view from Aksla viewpoint. A lot of stairs or you drive up from the back by taxi: https://www.mark-koenig.de/norway-places-aksla-viewpoint-%C3%A5lesund/

If you like bird watching I recommend Runde island - a day trip from Alesund. You can either hike the high hill or do a boat trip with lovely former teacher Johan.
https://www.mark-koenig.de/norway-places-bird-watching-runde-boat/

if you do Valldal the famous Geirangerfjord is not far. A boat tour (to / from Hellesylt) or a guided Kayak tour though the fjord will allow to see waterfall Seven Sisters: https://www.mark-koenig.de/norway-places-seven-sisters-waterfall/ and also "The Bottle" on the other side: https://www.mark-koenig.de/norway-places-friaren-waterfall/. Both awesome beautiful and at that time full of water.

From Valldal to North you could reach Trollstigen.

Glacier is a little more difficult. by public transport and smooth hike only. Nearest to my mind is Briksdalsbre which has also a provider that will drive you up a good part of the way, so you will have a last walk of 15 mins.

Last tip: From Bergen you could use Hurtigruten ship port-to-port to Alesund. If you do this on summer sailing plan (only) the ship will drive into Geriangerfjord from Alesund and back (morning to evening). You could also disembark in Geiranger by boat. With this "trick" you would have done the Geirangerfjord boat tour passing the Seven Sisters waterfall at the same occasion ;-)

Hope that helps. And again: At some occasions a rental car in Norway opens up more and different possibilities - a lot of them I did lot list here based on your briefing.

Just to manage expectations. In my eyes the recommendation Geiranger and fjord is still a full touristic recommendation. It is one of the 18 official scenic routes: https://www.nasjonaleturistveger.no/en/routes/geiranger-trollstigen

So, really no adventure or off beaten path. On normal "bad" days of full season you will find up to 4 cruise ships in Geiranger at the same time which will look like this: https://goo.gl/maps/gTRs9xmWyCm

Thank you both for your replies!

Tom - we are flying from Australia so we have to enter via Oslo. We also want to visit for at least a day or two so definitely not foolish ;) What fjords south of Alesund do you recommend, I'll add them to the list! Thank you again I really do appreciate it! :)

Mark, thank you also for taking the time to write such a detailed response. Renting a car is 100% out for us, so happy to rely on public transport.
Regarding your tip for Bergen to Alesund via Hurtigruten - is there a site that i can view their timetable?

Thanks again guys!! :)

There is no public transport through Trollstigen in early June.

Sailing plan Hurtigruten next summer. Take care to choose the right "season" which do not match with normal calendar seasons. Also choose the right direction. In your case "northbound".
https://www.hurtigruten.com/practical-information/sailing-plan/?season=Summer

Tip for booking: Besides booking by phone via US branch of Hurtigruten you can also book directly at Norwegian website (Norwegian language) - not so bad for Germans but for English good to open Google translate in parallel. Normally also cheaper. Did that few times.

https://www.hurtigruten.no/havn-til-havn

And again: Tip into Geirangerfjord only in summer season on northbound route.

Little European add-on info to Tom's US view which I share: Most tourists in Norway come from European continent and a huge ratio of them travel by car, motorbike, motorhome or other vehicle. Therefore cruise ship passengers are only part of the crowd in Geiranger and other ports - but also a mighty one.

Most scenic fjords are inside the land whereas Alesund is at the coastline. Beside Storfjord and branch Geirangerfjord you can also choose Hjorundfjord (destination of Hutigruten in Autumn), Austefjord or Dalsfjord but hard to get there by public transport.

Mentioned Olden is the entry village to the glacier I mentioned in #1.

few nights at the Juvet Landscape Hotel in Valldal

Don't see how you will reach this hotel on your dates without renting a car. I am sure too early for strawberries but Valldal has the best strawberries in the world ; seek out some of the jam at least which will be sold year round if you go.

The Trollstigen famous road may not even be open until the end of May (exact date depends on snow fall but past years I believe end of May is normal)

We did the NIN this past July and loved it. Especially the Flamsbana train from Flam to Myrdal and then we rented bikes and biked down. I did a trip report on this forum. It was awesome!