From my understanding the dipstick is meant to read full from a cold start and overnight after its all drained down.
Can you ask them how much oil they put in and try to find the capacity of your engine oil?
Letting it warm up sat still at least gets the engine warm. You wouldnt leave it sat till it's fully up to temp so a steady drive is always needed. Water pump and oil pump will get the heat circulating whether it's moving or not.
Echo what mica has said. Don't be phased by mileage either. I bought mine at 158k miles and now on 169k no major issues. I do have fsh which always helps.
The fuel plays a part too. Lower octane is more prone to producing detonation(knock). Again the mapper won't push the engine far enough to constsntly knock and regard the timing. Fuel can contribute anywhere up 10-15hp
Are you sure it's wheelspin and not clutch slip?
Unless tyres are bald, driving on ice or high power I wouldn't think it was that easy to spin the wheels in a straight line.