I'm pretty certain that there is no public transport from Voss to Gudvangen (or indeed direct from Bergen) in time for the 0900 boat to Aurland/Flam- 0910 is the earliest arrival I'm aware of- puts you on the 1100 to Flam.
Option 1 sounds like a good idea as the 0817 should be a very quiet train. Unless you've come on the sleeper train it's too soon to have got there from Oslo, and too early for any cruise passengers to have come up the line then straight back down. The point about being out on the water early is a valid one. I wonder about taking the 1015 boat from Flam to Gudvangen, the 1245 shuttle bus back to Flam, Otternes in the afternoon, then the 1924 ordinary service bus back from Flam to Voss (connecting train to Bergen).
Or continue on that early service bus to Flam, the 1015 cruise and 1245 shuttle return, then the last evening train from Flam to Bergen at 1825 (it has no Oslo connection, is after the cruise ships have departed so should be a quiet train).
As regards the cruise ships, if this forum is anything to go by, there seem to be huge differences in nationality as to what passengers do. The ships are docked around 0700 to 0800. Certainly among British cruise ships (or the ones I've been on to Norway, including Flam) you will find a lot of passengers (like me) who do things independently- such as vanish off doing the various walks around Flam (or up valley towards Myrdal), or have done their research and go to the other stave kirk near Flam at Undredal (for the goats and the cheese making as well as the Church), or use the public buses around Flam to other destinations. Even the excursion buses from British ships seem to do different and more interesting tours than the major international cruise brands- a comment not confined to Flam.
One small example of that would be the Aurland Shoe Factory- I don't think I've ever read on this forum about anyone going there.
One of the reasons I like walking the valley (apart from seeing it from a different perspective than the train) is being able to join supposedly sold out trains at will, and using the wayside stations which are there for the locals.
The British ships at least spread the load on the Flamsbana by some quite clever techniques, not just up and down the line on certain departures.
When I'm back in Flam I avoid the times when the Norway in a Nutshell in a day crowd are milling round the town, on their transfer between transport modes.
