This was inevitable given Tesla calling the system an 'Autopilot', when in fact the driver must have their hands on the wheel and monitoring full time.
Needless to say there's a huge difference between spectator and active participant. We're not at the point that a person can just sit back and read a book in a self-driving car, yet sitting there, hands on wheel, and doing nothing but watching - that can get tedious.
Using a soccer analogy, I can go to sleep watching certain Euro Cup 2016 matches, but if I were playing on the field, obviously that changes everything. With self-driving cars, I'm somewhere in the middle (basically, a benched player).
No, you don't, unless you want an exhausted pilot trying to land in a crosswind at the end of a journey.
Aviation autopilot is very much "set waypoints, sit back", as if anything goes awry it lets you know, loudly, and then you have time to deal with whatever needs dealing with. The whole reason autopilot was developed was to combat fatigue related accidents - and it works.
"and maintain situational awareness." Some failures can happen quickly, and the plane can change modes unexpectedly. Plus the warnings you receive may not be accurate.. see Air France 447.
You can sit back, but your role is to constantly check your instruments, your performance, your route, your radios and your environment.
Yes, but you don't need to sit there with your hands on the yoke, feet on the pedals, wired to the nines waiting for disaster to strike. I used to take a book with me for longer flights (when you're sat alone in a plane for hours flying over cloud things get tedious), as short of having a wing fall off there isn't all that much that can go very suddenly wrong - and most of the "very suddenly wrong" situations will kill you regardless. Keep one eye on instruments, mutter intermittent obscenities at the oil pressure gauge - but mostly relax.