Regarding the pilot cost question: 1 captain with all the skills and experience and proper salary. 1 cruise pilot, while said captain nods off in a cockpit bunk ready to leap into action if required, paid peanuts. So, 1.25 pilots. Cruise pilot then goes back to smaller jets from whence they came to refresh their techniques, achieve command, and if so desires move unto the sleepy ultra-longhaul single (almost) big jet.
Cruise pilot, during takeoff and landing, is trained thoroughly to move landing gear & flaps, bark & bite captain if he tries to kill anyone and touch a wrong switch, and read any normal/non-normal checklists as needed. Cruise pilots answer to the name of 'Rover'.