Book your Tropic flight for an hour after you arrive, if you arrive at Tropic early they can change you to an earlier flight if available, if you're late they will put you on the next flight. On December 23rd make a reservation as it will be very busy.
In my opinion it's just not worth the hassle to take the taxi to municipal. By the time you get a taxi and drive there that's a half hour gone, and then you have to wait for your plane. If you miss your plane there it's more of a hassle than at International where they're still expecting you if your international flight is late. Again, the 23rd will be a busy day.
Astrum helicopter does the Blue Hole tour. http://www.astrumhelicopters.com/