Are there any airlines serving HKG-HNL at all now? Hawaii doesn't seem to be the top hot spot for HK tourists, but I am not certain whether that is the cause or the result of no flights there.

IIRC, both SQ1 and SQ2 used to land in HNL. That was later changed to the west-bound flight only before SQ skipped HNL in both directions. CX never flew HNL in my recollection, and I feel that they never will (no business passengers).