The minimum prop listed for that motor is an 11X8, so an 11x10 may work although it will be pretty quick at that pitch. But, that's what the throttle stick is for.
A left bank is to be expected at slow speed, that's the airplane demonstrating it's at the edge of control and the motor torque is greater than the flight controls. Try a bigger nosewheel tire for better prop clearance. It will also give the wing a better angle of attack, helping the plane to fly off instead of jumping off with elevator.