Lyft drivers can decline a ride-request and they can also see where the passenger wants to go and decide if it's worth it or not. I can see some of them declining to go out to Kapolei since it's a 20-mile ride back to town.
Maybe, but it's risky. Most requested areas for Oahu (according to the Uber and Lyft sites) are Downtown, Waikiki, Manoa (where UH is), Ala Moana, Pearl City, Kailua, and Kaneohe. The closest city to Kapolei on that list is Pearl City - 10 miles away.