Nah, it's because the directors always decide they know better and end up drastically changing and ruining the pre-existing story. Ton of people would love to see a near 1 to 1 recreation of a loved game story made with real people but that basically never happens.
So yeah the same universe spin-off story ones work better because there isn't a pre-existing story to completely butcher and fans can be like "hey I get that reference" during it.

Some of them maybe but some require a check in via steam occasionally to run. Steam also recently (due to California's new law) changed the buy page to clarify you are buying a license to the game and not the game itself.
Devs can also at any time issue a command to remove their game from owners libraries (recent case of this being for The Crew)

I mean doesn't need to be a screen. A book, music, small puzzle, etc. Something to keep your mind engaged. When you aren't mentally engaged with something it's easy for some people to start worst case scenario thinking and induce panic attacks which aren't ideal to have in general let alone on a plane.
Same reason some people can't sleep in silence.