We stayed at Casa Firefly last year in Jan. (different owner) and enjoyed it.
As group of eight we mostly stayed at Casa and enjoyed each other and beach.
The Casa is not near center so it was 10-15 min walk to shop if we needed something. Okay walk for pleasure shopping and to and from restaurants even after dark.
We rented 2 bikes for the week, however rental bikes were not in very good shape. Check them out before renting, one of ours was barely useable. However the other was helpful for errands. They were not comfortable enough for longer trips exploring the area. Maybe you can find better. Long term visitors told us they had to bring their own.
We also rented two boogie boards for the week, again check condition before taking, one offered was cracked. Was a lot of fun to be able to run out any time and ride the waves in. However waves were pretty big, so take care.
Taxis were plentiful, often cruising by along the road. Or the caretakers called when we needed one, though plan ahead since caretakers mostly but not always there. For our group we took 2 taxis back to the airport since no vans were available in Troncones (at least last year).
We enjoyed tours with Alejandro of Costa Nativa Ecotours for bird watching and seeing the countryside beyond the beach.