Does propeller size affect total drag force of plane?
the drag force that a propeller generates while under power is expressed as a torque applied to the engine's crankshaft and arises because of skin friction on the propeller blade surfaces. as long as the prop is generating net thrust it is not generating drag in a direction opposite to its direction of travel.
Prudent design of the prop blades guarantees that no portion of the blade is ever generating backwards thrust for all possible combinations of airspeed, RPM, and blade pitch.
A propeller that is not generating thrust is generating drag which does act against the airplane's direction of travel.