All good info, but I'm really interested in why I can't see hawaiian first awards on delta and united with miles but I can with AA?
Since no one has offered an answer to that, I'll hazard a guess: HA has a somewhat closer partnership with AA than UA or DL, and it may be that AA can do first class interisland awards and the others can't. But you'd probably need to call UA and DL to find out for sure, and even then you're as likely to get a made-up answer as a good one.