ORIGINAL: John 3rd
Just might answer for the sake of taking Hawaii.
I've always felt that if one could take PH or render it unusable to the American Fleet you would mightily advance the Japanese cause. It totally turns the axis of probable attack on its head. Having Midway, the Line Islands, and Hawaii would create a massive line from which the American Commander would be force to either (1) go north through the Aleutians, (2) start down in Suva/Pago Pago, (3) work from Australia, or (4) come from India. The capture would massively expand Allied supply lines as well as take an excellent anchorage/repair yard out of the picture. Note that I don't HAVE to take PH. Having everything but PH still achieves the same thing.
I think that there is a problem with this: Hawaii are so far outside of Japanese perimeter, that even transferring planes there is problematic (Allies can cut off Japanese ability to transfer fighters there by taking Midway and Johnson simultaneously, and these islands are too small and isolated to be effectively defended). Also, fuel costs for supplying them and maintaining active operations must be kept in mind when playing RA. I found Hawaii (without Oahu) somewhat of a trunk without handle - hard to carry, but too valuable to drop.
That said, my Hawaian operation did miracles in attriting Allied fleets. I exchanged 2 old battleships for 8 there, and still can enjoy local surface superiority in some areas in 1/44 as the result.