Go for it.
As far as upgrading the motor, maybe, maybe not. A bigger motor may draw too many amps for the ESC and burn it out.
Ailrons are control sufaces on the wings that control roll. Without ailerons if you try to hover the airplane will spin out of control. The ailerons are needed to counteract the torque of the motor.
Neither of the planes we have discussed have ailerons.
The GWS slow stick has rudder and elevator and the Slo V has a V tail that only gives rudder like control.