If you look outside, you are much less likely to get motion sickness vs, for example, looking down at your phone. I get to try it every time I go to a theme park, on a fast rotating ride, if I look inside, I get dizzy and sick, but looking outside makes you resilient.

Yes. Also the driver can anticipate the various accelerations more accurately than the passengers since he is causing them.

As a passenger I find I can read in reasonable comfort if I can look up and out of the vehicle at each acceleration i.e. at turns, when stopping/starting.

The "neurotoxin response" theory that the author doesn't like would say that this is because you anticipate the movements perfectly because you're the one causing them.

This.

I used to take a coworker on kamikaze night runs up and down the california coast in my track car. He would envision he was driving to avoid motion sickness. Imagining braking, steering, blipping the throttle, shifting gears, operating the clutch, everything as if he were playing a video game.

One night I decided to test it and started driving poorly, braking early for turns, picking the wrong gear, or just not accelerating hard out of the corners.

He became angry and sick immediately, we had to keep pulling over for him to vomit. It was uncanny, we had been doing this stuff every weekend for months without any motion sickness issues ever. The moment I started driving unpredictably - it wasn't even driving poorly, just not what he expected, he fell apart.

I do this as well and it doesn't always work like you described. Unexpected breaks are the worst. I also feel less sick if I am sitting/standing sideways to the direction of motion. Somehow I don't feel motion-sickness at all on water, air or trains, but just on road.

Most taxi rides give me a strong motion sickness, while regular car rides do not. My assumption is this is due to the more aggressive and unpredictable driving style (quick, unexpected lane switches and turns), so I think this more or les correlates with your coworker's experience.

This leaves something to be desired -- it's very difficult to tickle yourself with your own fingers, but easy with a feather, even though you know you're doing it.

The act of tickling yourself is a two-way sensory exchange. You feel your fingers and your fingers feel you, whereas with a feather you don't have the latter.

By comparison, it's also easy to tickle the roof of your mouth with your own tongue.

It is, because when you are steering, you have much less sensory conflict. You hold the steering wheel, which gives you input about e.g. the cars motion, and even more, you are actively guiding or causing the cars motion, both with steering wheel as well as with gas and brake pedal.

I've been able to get motion sick while driving in traffic.