I would take booties but not wear them.
If you do happen to cut your foot on the reef the peace of mind you get from wearing booties from thereon in is worth the hassle.
Nothing worse than hitting an already open reef cut on a rock or more reef. Or the fear of doing so, as no matter how much you strap / protect the cut it always comes off in the water.
No matter how careful I am, I always end up with cut feet.
Another top tip is as soon as you get there get a tube of Neosporin from Mana foods in Paia ($12). If you get a reef cut, clean it up and drop this on 2x a day, it's magic (Matt Pritchard gave us this one).
I'd always take the insurance on a rental vehicle, yes it doubles / triples the price, but all insurance is a waste of money until you need it and I've heard horror stories in Maui.......
Take or buy a padlock key box and lock the car key in there whilst in the water.
Also, I've got great deals on brand new large SUV's etc from the website below;
www.discounthawaiicarrental.comIf you want a van then Kimo's has been good previously.