We love shore diving in Hawaii! You'll have a great time.
A few important differences between shore diving in Maui and Bonaire -
- trade winds - the seas get rougher as the day goes on, so most diving (shore or boat) takes place early.
- parking - another reason to get your shore diving in early is the general lack of parking at most good sites. Try to get there by 8am at the latest. And sometimes, the parking is bit away from the entry.
- rinse tanks - I can't think of any dive shops that have rinse tanks, but there have to be some (maybe?). We did our rinsing at public showers at the site (Mala Pier, Makena Landing) or back at our accommodations. We usually buy two large plastic tubs at a Target or Walmart and use them to lug and rinse gear.
Whatever footwear you used on Bonaire would be fine for Maui. I don’t know if there are ostracods, but rent a tank, do a night shore dive, and let us know what you see!
My favorite sites on the island are in West Maui (Mala Pier, Slaughterhouse / Honolua Bay) but they're roughly 45 mins away from where you're staying. If you're willing to get up extra early, they'd be worth the effort.
In South Maui by you, we liked 5 Caves and Makena Landing the most. Ahihi had nice healthy coral, though you have to drop your gear quickly and park a little ways down the road.
There is a Maui shore diving book that we bought, but it was pretty outdated. The best sources of information we found were the dive shops where we rented tanks and here on scubaboard. If you'd like a guide for your first few dives, I'd recommend Shaka Doug. We had a good time with him.