Sounds like a good plan! We did a lot of these things as well. We also really enjoyed Discover Hawaii Tours, we also did a Pearl Harbor tour with them from our Waikiki hotel.
In the North Shore, we loved Kono's! It's a very casual quick service place and you eat outside on picnic tables, but it was one of the best things we ate the whole trip! Would be a good lunch stop. Also recommend stopping at Matsumoto's for shave ice. We loved it so much we bought t-shirts! lol
When you do the couples massage at Aulani, definitely allow time to enjoy the hydrotherapy gardens before and/or after your massage. We thought an hour was good but others prefer longer. Also, if you are getting to the pool mid-day and have trouble finding chairs, we always had success finding them on the deck in front of Ama Ama.
Lastly, don't underestimate how long it will take you to get to Kualoa Ranch. we had 9:15am tour there and they required us to be there at 8:30. We left around 6:45 and between rush hour traffic, an accident, and single lane highways on the windward side, we got there right on time at 8:30. Also recommend booking your tours in advance to secure the times that work best for you - they do fill up and some tours are only offered once or twice a day.