If you have a painfull left foot it sounds as though you have an excessive amount of fixed trim tab applied. A good reason why you should not push it on the pre-flight, or back it into the hangar door.
With many light aircraft the turn and slip may not be mounted horizontally resulting in the ball being slightly off centre.
If the aircraft is out of balance it is effectively going slightly sideways so which causes more drag, the rudder or the fuselage?