The parking is awful. I wouldn't recommend if you have a rental. It's also located on a single lane road with local vehicles half on the edge. There is a small pad up front that can hold 2 vehicles. That's assuming its available, and you can maneuver your vehicle into it.. long story short definitely don't recommend with a rental.
We did an island tour and a beach stop was included. We arranged the tour thru the front desk and then walked less than 10 minutes around the. Irene if he post office to catch the tour bus. The taxi from the airport was $9 a person if I remember right. Ask to share a ride- the more people lowers the price and there is a limit to how many they can take. Regarding the ferries, I walked to the dock (about 20 minutes) to scout routes and prices. Round trip was cheaper and did not have to be used the same day. Will give a senior discount but didn't know to ask for it til too late. It's easy to visit another island via ferry but not cheap. Bunker Hill staff are very knowledgeable and helpful to navigate- definitely use them.