Hawaii is one of my favorite destinations. For several years I had the good fortune of traveling there for several times a year.
The Arizona Memorial is definitely worth the trip. Currently, they aren't letting people visit the memorial over the ship, but they expect it to be open again in March. The displays at the visitor's center are great, and you can easily spend a couple of hours looking at everything (normally, while you're waiting for your turn to go to the ship). Including a visit to the memorial, I'd budget 3-4 hrs.
The USS Missouri is anchored at Ford Island and you can tour it for a fee. I haven't been through that particular ship but I've toured the USS Alabama, which was the next class of ship. If you've never been on a capital ship it's worth seeing. It probably takes an hour or two to get though it, but I'm guessing.
There's also the Pacific Aviation Museum on Ford Island. It has a nice collection of airplanes and artifacts about Pearl Harbor, and it's in one of the old 1941 hangars next to the old control tower, and being on Ford Island is part of the museum experience. You can probably get through that museum in an hour.
If you want to try authentic Hawaiian food, visit the Side Street Inn in Honolulu. Bring cash, and be prepared to wait for a table, but it's the best local food in town. Anthony Bourdain visited it during the Hawaii episode of
No Reservations.
I always find time to do some glider flying at Dillingham Airport on the North Shore, but it's about an hour from Waikiki. There's a couple of operators there where you can book a sailplane ride. Here's the one I used to fly with:
https://www.honolulusoaring.com/ The views there are spectacular! (This site is for pilots, but you can see some photos of the flights here:
http://higlideracademy.com/photos/ )
There's a couple local CP guys, so they might have better ideas, but this is my short list.