I live in Hawaii as well and try to book all our travel on Delta or Hawaiian because the miles move back and forth very easily. Our travel is mostly to the West Coast and Inter-Island so Hawaiian is awesome. We don’t have a Delta Credit card but do have a Hawaiian Air Visa—IMHO it sucks though and it won’t survive its next renewal.
If you are using JAL (OneWorld) to Japan then you may want to consider the Citi American Airlines card
. That way you could funnel miles to AA (also OneWorld) and fly to Ohio/Florida or vice versa. Many airlines and options using this model but the questions Scoach asked are important to consider.
Because you don't use hotels and rental cars often you are a prime candidate for an airline specific rewards card. We often use hotels, rental cars along with airlines so a cash back or generic points card works well for us.