In a previous life (segment) I spent about 5 months on Maui. I loved it. BUT! I didn't live there for more than a bit over a month at a time, so I always knew that in 4-5 weeks I'd be back in Austria. Yet I still noticed a couple of things that didn't make it to your list:

1) Public transportation. OK in the US public transportation sucks most everywhere, but if you're on an island (Caribbean or Pacific Ocean) don't expect a tram or subway to be available. If you're lucky enough to get a bus, they are going to be few and far between.

2) Medical services. If you get injured or if that giant friggin' centipede bites you, it is a long ways to the nearest hospital. If you have a serious but rare problem, unless your are REALLY lucky you're not going to find a specialist without getting on a plane, and that may not be possible in your condition.