I've never been to Hawaii so I can't advise you about shooting there.
In general, I would not bring a lot of gear. On most trips with my wife, I bring a 35mm SLR and a couple lenses (wide, normal, and a tele if I think I'll need it), and she brings one 35mm SLR and a standard zoom. We also pack one 35mm point and shoot, usually an Olympus Stylus 100. We're both into photography so there's no argument about bringing cameras, but we agree on not bringing a ton of stuff. I buy film at my destination if possible. One time we went to the beach and I brought practically everything, Mamiya RB67, several Nikons (digital and film), all the lenses I owned, the works. Almost all of it stayed in the bags the whole week, taking up space in our tiny B&B room. I ended up shooting one roll with the RB67 and a few with the F100. After that experience, I've tried to keep the gear to a minimum.
One more thing - I do pack a light tripod whenever I travel.
My best shots were 28mm lens, polarizer, and Velvia 50.
I would expect the only real light you will expect to get if you take your gear is the laser light from your wife's eyes as you attempt to take pictures.
my 2cents is take no equipment and have the time of your life, unless of course she is a photographer as well and dragging her own equipment.
Bring something really simple, like a Yashica T4. Point. And. Shoot. I can tell you from personal experience that focusing too much on photography while your wife is around, will quickly kill the joy - for her! Choose your time to photograph very very wisely. Include her in as many of the photographs as possible, if she doesn't mind. Really. It's your honeymoon, after all. A memory of your first adventure together as a married couple.
Well, I took my 4x5 to Maui last yr, but pre-negotiated with my wife about it. I took exactly one color shot on Ektar, and paid for it dearly by having to spend most of the next day window-shopping in Lahaina. But it was exactly the one shot I wanted. And since we were staying right on the shore
beside beautiful lava formations, I did sneak in one black and white shot too while my wife was napping. Our honeymoon twenty years before was in Kauai, and I took the 4x5 then too, shot it very
very conservatively, just when my new bride herself was in the mood to shoot the Nikon. We're going back to Kauai this coming Spring, probably again with the 4X5, which I'll use only a few times,
but make each shot count.
As has already been said, keep it SIMPLE! Just one camera, one lens, and let it be an adjunct to your activities together, not the focus! Don't be an idiot and ruin the honeymoon by giving your camera more attention than your wife. You'll have the rest of your life together to take photo vacations alone or together; there is only one honeymoon per marriage. Don't start out your marriage by showing your wife you actually care more about something else than her.