Thanks Eric, after a bit of Internet research I've found that although Julia is correct saying that the flights are with United, it's one of those code share deals where we will fly either with Hawaiian or Island Air, depending on the flight time. Island Air allowance is 22kgs and Hawaiian is 23kgs so I will take 23kgs as a rule of thumb until the final paperwork arrives. I always end up taking the whole allowance - I find the suitcase is full before I put any clothes in - the shoes, toiletries, chargers, etc take up so much room!
Bren, yes I got the letter regarding the hotel change. The new one looks fine, but then so did the other one! I've seen a few negative reviews about the Oahu hotel which appears to be due to be demolished next year, but I do try not to pay too much attention to the reviews and trust that JY wouldn't put us in a terrible place.