Just sharing what I've found as of April 2024, since the information in the Rick Steves Norway 5th Edition guide book is a bit outdated.
We're ferrying between Flam, Aurland, Balestrand and Bergen without a car. Staying 2 nights in Aurlalnd, 2 nights in Balestrand.
Ferry option from Balestrand to Vik to see the church is operated by Norled (https://www.norled.no/); look under "speedboat and ferry" link. Since the church is only open until 17:00, choose the 7:50 departure from Balestrand and the 11:35 return from Vik.
Ferry option to get to Fjaerland is Glacier Tour (https://www.glaciertour.no/). For a round trip from Balestrand to Fjaerland, there is 1 time option departing Balestrand at 12:10 and returning at 16:45. You can opt for just a round trip ride on the ferry and spend 2 hours exploring Fjaerland. About $88 USD for 1 person (less expensive option compared to the 2 options below.) There is also a tour that includes a bus up to the glacier museum.
Fjord Tours (https://new.fjordtours.com/en) is another option I found, but offers only a ferry-plus-bus-to-glacier tour (can't book just a round trip ferry ride.)
There are RIB boat tours operating out of Balestrand as well; found by searching online. You may have to opt for a private tour to go into Fjaerlandfjord.