Yeah, don't waste your miles, the tickets are cheap enough that you should buy them outright. Unless you have no value for your miles or they're orphaned or something....
It's like a 20 minute flight, I wouldn't sweat it.
Lol, yeah. It's ~70 miles air distance. You won't have time to be uncomfortable, you spend nearly as much time taxiing to the active at HNL as you do in the air.