as far as the whole kook thing goes, if i saw someone wearing booties (or anything out of the norm for that matter) in the lineup i honestly wouldn't care a bit. probably be happy to see someone who wasn't so damn self conscious when surfing all the time. the amount of thought people put into their "image" these days is ridiculous. locals however, might think differently. i've never been to maui so i have no idea what it's like there, but in puerto rico i have seen locals wear reef boots, not very often though. people there won't give a **** what you wear as long as you don't drop in on them, the people are just way too colorful to pay attention to every little detail of someone's getup. the reefs there are probably just as sharp, maybe sharper (not to mention the unfortunate abundance of sea urchins). i've been cut a few times, but i could have avoided most of them by not letting my feet down after bailing. the biggest problem there is usually paddling over coral because unless you're in the right keyhole, you can find yourself stuck in extremely shallow water. that's one of the reasons there are so many body boarders, they can just zip right out by kicking with their fins.
i guess if you have to literally walk on top of the coral to get out to the lineup, then having boots would make sense, but other than that you should be okay. get them just in case and see if you like them, if not at least you have them if you do end up cutting your foot on the reef.