6 days to get an appointment is not that bad. That is better than what I recently experienced with my Hyundai dealer, who initially wanted me to schedule something 17 days out [but found a way to fit me in within 5 days due to the nature of the problem].
I was seriously considering an Equinox or Terrain as my next vehicle, but then see videos such as this which give me pause. I have owned 5 GM cars over the decades and they all had problems. Some more than others.
The headliner just needs to be replaced under warranty. That should be a no questions asked fix. The seat belt recall should also be easy. The power steering issue may be a little harder to resolve unless a code was stored or the dealer can reproduce the problem and figure it out.
I understand the guy's frustration with his brand new car, but he needs to give the dealer a chance to start solving the problems. He may literally be 6 days away from being satisfied, but needs to at least give the dealer a chance to look at it.