Q1&2 : No, I would not flip the switch. Apparently these five people are to stupid to realise that there is a trolley heading their way and refuse to get off the track.
That, and the world is getting overpopulated as it is.

Q3 : I don't have any friends, only acquaintances. But looking at my answer to the first two questions, they don't deserve to be sacrificed.
And Evil is in the eye of the beholder.

Q4: I bought a 20-year-old Seat Arosa recently.....so I would say yes.

Q5: No. These kind of cars allow their drivers to pay less attention to traffic. This is dumbing people down.

Thanks for organizing this @bengy. I enjoyed thinking about your dilemma's😉