Regarding the P factor.

I read an article once where Mustang fighters were used as an expample of the P factor.

With the brakes on there is no P factor as the prop on both sides sees the same air. But as the plane starts it's takeoff roll the air is coming into the angled back disc at an angle. Because of this airflow and the angle of the prop disc with the tailwheel on the ground the upward traveling blade is seeing a much smaller angle of attack than the downward traveling blade. (If you think up and down blades then it doesn't matter which way the prop is turning) So the downward moving blade gets a bigger bite and pulls harder causing the plane to want to veer away from the down moving blade. Once the tail comes up and the angle of the blade disc to the airflow is reduced then the P factor is reduced along with it.