We did those islands in 2024.
1- We really enjoyed Toa Luau on Oahu. It's North Shore area, run by local families, and entrance also gets you into Waimea Valley Waterfall and Gardens. Was a really nice night all around for our crew, and bookable on Chase Travel portal so we did it with CSR 1.5x points for some added savings. We were looking for a luau fully under control of a local business, versus something run by a major hotel chain, etc, and this one was lovely.
2-
Where to begin?! Sleeper hit for us was Hilo on Big Island. We loved that area, it felt much less touristed than anywhere else we went. We got a VRBO in the Oceanview Mauna Loa Shores which is right at a beach park with sea turtle visitors, just up the street from a really cool black sand beach (Richardson) and easy access to the rest of Hilo. We were using SW for island hops and were able to fly direct Oahu-Hilo, did a couple days in Hilo, used our Volcano National Park day as our transfer day from Hilo to Kona, and then flew Kona to Maui for our next hop. Our original plans just had us on Kona for our whole Big Island visit and we were so glad we split because Hilo ended up being really exceptional.
Hanuama Bay on Oahu is unbelievable. Do your research about how to snag reservations (they only open a few days in advance, are closed certain days, book quickly, etc) but your Disney VQ and LL skills will translate well into snagging a good spot and then having the most amazing walk-off-the-beach snorkeling experience.
We opted to pay for a private guide for our Road to Hana. It was the biggest excursion expense of our trip but there ended up being a lot of traffic and we were really glad that we weren't the ones trying to drive. Our guide had some interesting stops that I doubt larger groups could even do: at one point he pulled over next to what looked like any other tree and had us shimmy through an opening you could barely see from the road. We ended up walking down into this incredible underground cave with tree roots growing down into it, absolutely stunning. I'm sure a larger tour group wouldn't try that because the space underneath would be way too tight. Not sure if the self guided tours direct to it, but even if they had I don't know that I would have had the confidence to climb down without the guide there telling me. We did lots of other hikes, waterfalls, etc on our own, so I'm not opposed to creating a self guided tour, but I'm glad we splurged for the Road to Hana.
We hiked, kayaked, snorkeled, etc, with a combo of booked excursions and self guided tours. I don't want to blow up this thread any more but, if you want to PM me your email, I can send you docs I created and the specific tours we booked at various locations.