Crowds? On any given day there are only about 200 tourists on Moloka'i. In 2005 just under 75,000 total. Oahu sees about 15,000 a day, that's about 5.4 million a year.

Kalaupapa can only be done as a day trip if you fly in on a tourist charter. The mule ride has info about this on their site.

A hike down the cliff isn't too bad but then you must hike back up. It may be 2,000 feet but there are a number of switchbacks that make it managable by foot.

I really don't put a Dash 8 in the prop category, even though it is a turbo-prop. It rides a lot like a small jet. Props don't bother me except as I've gotten older I am more likely to get a little queasy on small single engine planes.