1) Allow about 30 mins I would say.

2) Yes assuming your flight is on time and no problems at immigration

3) Something like that, yes. Light blue cab.

4) Whenever I have been at the buddha there have always been a few cabs waiting, but you might as well get a bus if one is going soon: the travel time will be very similar. Note that the Tai O markets tend to wind down quite early in the evening...