A couple of quick things come to mind:
Go to Casablanca for dinner (#1 rated restaurant in the new Scubadiving top 100). Although I think the rating was biased by a lot of Bonaire supporters responding. It's good, but not that good compared to other places I've been in the Caribbean. A nice(pricey) dinner spot is it rains fishes, kind of hard to find (and park) it's on the north end of the main street through town, right where it becomes one way south. Great sunset views of the harbour. We also liked Donna & Giorgio's for pizza/pasta.
The boats at Toucan leave at 8:30 - sharp, it's probably the only thing on Bonaire that runs on time, everything else is on "Island time" One afternoon we noticed a trip posted on the dive board for an early afternoon trip if 2 more people signed up. So we did and wound up on a boat to Klein with only a dutch couple and ourselves plus 2 crew for $18 each. It was like having a private charter.
When you're going towards the Airport from Plaza, watch out for the Donkeys where the road turns, especially at night, there's no lights. The Sanctuary is about 1/2 mile from there but they get out and hang out by the road because the tourists stop to feed them, it's not encouraged as several get hit by cars every year.
One last tip, pay your departure tax($20) and get your receipt before you get in line at the check-in counter. You have to have it before you check-in/clear customs. You get it at the booth at the airport on the northside of the terminal.
If you're leaving early in the AM the car rental places won't be open before 7 or so, just drop your bags at the gate and park at the curb, then return the car after you've checked in.
Have a good trip,