I've traveled the Caribbean a bit having been to Curacao in 2008 and it's sister island Bonaire 9 times in the last 5 years. The diving is similar at both islands and they've taken a pretty good hammering two years ago from off shore storms and the resulting wave action. This has some serious damage to most corals and sponges down to 30' or so. Most of the shallows were devastated and are mostly rubble.
I just came back from Curacao and also stayed at Kura Hulanda. Please be aware of certain facts. Take bug juice. The skeeters are very active and there are lots of them. The lodge is OK by my standards, but a bit spread out and the rooms were too small. There is lots of foliage and flowers. So much so that even the ocean view rooms don't have much of an ocean view. The pool is decent and the temperture is about 90 degrees F. Food is good, but way way overpriced ($21 for standard breakfast buffet). Sol Food is not only a better choice but almost the only other choice. Don't bother with Rancho down the road. Stay with Sol Food. Just for Sunshine's benefit I'd also add that when you eat there you will not go away hungry for food---or conversation. Man, can that woman talk!!!
Ocean temp is just about 84 degrees F and viz averages 60' to 80'. The reefs were quite a disappointment to me, especially the house reef. They can't help what mother nature has done, but there was very little marine life compared with what I'm used to seeing. Right around the corner is Neptune reef, clearly the best reef on their itinerary for marine life (watch for the turtles). This also makes for very nice night dive, much better than the house reef. Most of the action and life is above 50' after dark so no need to go deep. Mushroom Forest and Watamula are two famous dive sites there. Not what they were a few years ago, but the coral and terrain itself make them interesting; just not much in the way of critters. Maybe it'll change by the time you get there.
The dive op is a good one with Amy, Derk, Robert, and Jarrod leading you. They go very slow so you can take your time and look for little critters. There will be a dive mater at the front and one following to watch stragglers. Their breefings are thorough so listen to them. They sign you in each day and then do a roll call as the boat leaves the dock and again after each dive---no divers left behind. Most dives are very close to land so getting lost is not an issue. If you plan to do a night dive you'll have to arrange for tanks before the shop closes at 5:00. If you are taking your own gear there are lockers and they are secure (locks are supplied).
For what you are doing I don't know if I'd bother renting a truck. Shore diving other locations can be done, but there is a lot of driving to get to them and the roads aren't marked very well. Having been both places I'd say if you want to shore dive then go to Bonaire, hands down. If you want to go to town then tae the shuttle on an off day. Besides, driving around town can be pure hell when compared to the states unless you know where you're going, which you don't.
That should suffice for now. PM me if you have any questions in particular.