It is common that people confuse moment with movement.
It is true that for a rotating system, the rotational axis precess at 90 degrees to the applied moment, BUT it dooesn't change the direction of the moment. Thus the aircraft is subject to a left yawing moment created by the difference in AOA of the propeller blades. This moment is balanced by an equal and opposite moment caused by our application of right rudder. If the net moment is zero, there will be no angular acceleration and the aircraft will fly in a straight line.
If the net moment is not zero because we fail to make corrections with the rudder, one has to consider the complete system of the rotating propeller and the non rotating airframe. The propeller itself responds with a 90 degree precession, i.e., pitch-up. The airframe responds with no precession and yaws to the left. Depending on the relative moments of inertia and the angular momentum of the propeller, the combined system will react with a combination of pitch-up and left yaw, i.e, a precession of torque that is less than 90 degrees.

/Red B.

Mostly mostly true, unless you are flying hard enough to have gyroscopic effects exceed p-factor as they do during aerobatic flight. Higher G pulls with a high pitch rate require left rudder if the prop rotates CW, and it would need right rudder in your Chipmunk.

:-D