Talk about confused! What's going on here?
Remember your are a tourist. So tour!
You want to go to S.D. for a day trip? That is, get there and then walk around the old city, and the malecon, etc? Just get on an express bus from B.C. to SD. 30 minutes later, DA, DA!! your there. Walk, ask, get lost, find yourself, enjoy. How hard can this be?
Want to go to Sosua? Go!! Get on a bus in SD and get off at Sosua. Safe, efficient, inexpensive and predictable. Look out the window . You will see the same countryside as a taxi.
If you want to pretend that you will stop all over the place and drink from gurgling brooks, etc. then pay a taxi driver for 9-10 hours of driving , use of his cab, gas, rest stops, etc
By the time you find an airplane, get to the terminal, hope it takes off, ( it's guaranteed to land. lol je,je,je), lands, and you find transportation to your final destination it should be very close to the next day.
I am saying relax, It's all very easy. Jrzguy seems to do do this to himself each trip he plans and winds up in the same place, doing the same ol', same ol'. Or it sounds that way. Always regeting. Never getting. Bueno suerta, John