Wrong, there is literally a crew that doesn't even let oil dry dust sit on the track.

Wrong. Tracks do have clean-up crews, but they can't prevent debris build up in a single session (which does happen and can be significant enough to cause bad chipping). Crews also don't go out between every session. Spills tend to get careful cleaning, but debris (as mentioned in the comment you replied to) doesn't always. Note that this varies by track and may also vary by area.

Wrong, plenty of cars wear out the outer edge before the rest of the tire, I work for Infiniti and see it all the time.

Some cars wear the outer edges without track use because their alignment is poor. Track cars that are also street driven tend to wear one side or the other, as street driving and track driving need different amounts of tire. It's also extremely rare for street driving to cause chunking and graining like track driving does. Of course, all of these are easily eliminated by putting on a different set of tires.