jaysue - good point about only one pool at AKL. I had also always thought also it was because of the number of visitors to AKL to see the animals and how busy Boma is. It's probably just a popular resort to visit.
I have stayed at BCV twice now and have seen many, many people who do not have wristbands. And they don't have pool towels either - they can't get any without a room key. I doubt they could use the slide either - someone would notice?
On the other hand, we were never asked for 5 room keys when we all went to get towels/wristband - all they ever saw was one for the whole group.