To answer your doctor question,
Doctors reduce the amount of health required for each traning session. The more stars, the less health it takes! I hope this helps.
The role of the Doctor influences how much Health your Driver(s) lose per Training. They are based relative to your level:
5 star rating: -10% Health
4 - 4.5 star rating: -11% Health
3 - 3.5 star rating: -12% Health
2 - 2.5 star rating: -13% Health
0 - 1.5 star rating: -14% Health
Morale has no influence on Staff, but can have a small influence for Drivers.
