I''m a beginner too, and if I were in your shoes I would try a better servo; there are Hitec Servos for $13 that offer ball bearings and are rated at 20% faster (if you are using a 4.8volt battery, the speed for your servo is .24s, and the hitec is .19s). Extending the control surfaces past the edge of the wing will change the entire shape of the airfoil at any position, making your plane more unpredictable. You can even step up to faster servos with more torque, and any servo upgrade you can use in the future on you more advanced planes.