The IDL is opposite the prime meridian (GMT), which was chosen over various other contenders for naval and rail reasons; it's not a coincidence the IDL is opposite the prime meridian. The "planet's day" is not a real thing, given that a new day is always beginning somewhere. The IDL is also not a line as it has to avoid Russia and other nations.

The IDL is where it is *because* of UTC - it's exactly opposite the UTC line. So using the IDL wouldn't be neutral at all (and there isn't such a thing as "neutral" in this case anyway).

You can track where the eyes are looking (i.e. the intersection of the eye gaze direction with the surface of the screen), but this typically involves a lot of calibration, and often more than one camera, just to make it reliable. Even if it's reliable, it's horrible to use - they have these on display at conventions all the time, and they're generally used for checking if advertising works. The other is to track the position of eyes in an image and a rough direction of where they're looking. You can then use this information to augment the image captured from the camera to make it look like the eyes are looking at the camera (when in fact they were looking at the screen, as in video-conferencing). I suspect this would be the more likely technology to make it into a tablet/laptop.

If the pizza was soggy then it wasn't Scottish. We deep fry our pizzas, and they come out crispy and left-ventricle-unfriendly. Otherwise it was probably from one of the many Italian restaurants, and it's hard to find a decent one. You can tell a bad one by looking in the window for a picture of Sean Connery with the staff.