They all have an impact. But the most important key to the success of a beginner is getting around the track in piece. So Race Day tuning has more importance than the other things you listed.

Open ESC/17.5 motors are insanely fast. Some new people have talent and skill and can put together 20 plus laps without tapping the pipes.

Other beginners can't drive a straight line at those speeds and end up breaking something.

If a beginner can't handle the speed, then Race Day Tuning goes out the window and all of the other aspects you mentioned won't matter.

Slow the cars down with motors and Spec ESCs, and then they can learn to drive. Once they learn to drive, THEN all of the other things you mentioned come into play.