My wife and I honeymooned in Hawaii last year. We stayed in Kauai mostly, but also took a Norweigan cruise around the islands, which stopped in Maui for a couple days. The first day we were there, we rented a car and drove the "Road to Hana". I've heard mixed reviews about this adventure, but IMO it's worth the trip. It's a LONG trip (about 50 miles) through very windy roads. A little nauseating at times due to all the curves, but the views are spectacular. Take your time along the way and stop from time to time to take short 10 minute hikes to view waterfalls and take a dip in swimming holes.
Our favorite adventure in Maui was taking a bike tour down Mt Haleakala. We did a tour which took us up to view the sunrise (seeing the sun rise at 10,000 ft elevation is truly amazing). We then biked down the mountain road. This bikeride was one of the highlights of the whole trip. The views were spectacular.
Sorry, I don't have much advice re: food since we ate on the cruise ship.