My first try would be an 11x4 prop or an APC 11.5x4. After ten or twenty flights you may feel more comfortable with the faster landing speed and work back upto the 11x6. I did this to learn to fly my Kaos. Be careful about getting too slow on the landing approach[&o].

Losing some weight can be a big help. A four ounce change in a 40 size plane is fairly significant. Foam wheels, wood prop, physically smaller NIMH battery, mini throttle servo, arranging items to get rid of balance weight, etc.

A turn or two on the aileron clevises shouldn't drastically effect the performance of the plane.

Flaperons don't go back to nuetral when you excerise the ailerons.

Carl