My advice to anyone considering living in Kauaʻi would be to think carefully about your motivation and expectations. I have seen it as a bumper sticker for another island - "Don't change Molokai, Let Molokai change you" - but it is the best expression of an attitude that applies equally well to Kauaʻi. That is, to thrive on Kauaʻi I believe requires a humility to come there with an open mind, willing to be flexible, accepting things as they are, and endeavoring to learn and contribute. With this mindset I don't think you can go wrong.
Another way of putting it would be do not come with expectations that things should be different, that your ways of doing things are superior and should be adopted, or try to remake your mainland environment on the island. People with this attitude are the ones that I believe get spit out, probably as much for their own good as for that of the island. There are a few enclaves on the island that feel much like mainland culture transplanted here for the nice weather with the look and feel of Southern California (I refer to Poipu and Princeville and the Kukui Grove mall). These places, to me, don't feel like Kauaʻi and I would advise against trying to live here if these are the only places you feel comfortable.
The material advantages of life on Kauaʻi are so obvious I won't list them; if you are thinking about it you already know them, they are relatively easy to experience just visiting. It takes time but finding friends and acquaintances on the island is perhaps the best the island has to offer.
While the Garden Isle may be as close to living in paradise as is possible these days, there are some definite downsides one should be fully aware of.
- tsunamis
- hurricanes
- floods
- chickens
- mosquitoes(*)
- rats
- roaches
- centipedes
- feral pigs
- local politics
As they say with water safety, "if in doubt don't go out" the same would apply here: if you aren't absolutely sure about living in Kauaʻi you probably are not ready. It's not a question of how Kauaʻi might change to be more suitable, but how you might change perspective to fit in as it is. If so, next vacation the island will probably either nudge you one way or the other.
(*) For me, Kauaʻi mosquitoes aren't nearly as annoying here as my experience elsewhere: the bites are only noticeable for a short time and heal quickly with little itching. Of course everyone's reaction is different but many people tell me they don't mind the local mosquitoes much at all. When the trades die down or anywhere there is standing water of course they can come out in numbers (working in tropical gardens like the NTBG Allerton garden there are plenty of places they are a problem) but I haven't seen them swarm here yet. By the way, I recommend picking up an all-natural noni-based (see left) insect repellent as most effective.