Flaperons: Up or Down?
I an ideal world you would have flaps and airleron with your transmitter programmed such that...
1. For aerobatic flight the flaps would move in the same direction as the ailerons for roll (to improve roll rate) and the flaps would move in the opposite direction to the elevator (to improve pitch rate). If you were ambitious you could try making the airlerons move in the opposite direction to the elevators too, but you'd probably only want to do this when you've got pretty good airspeed. Doing this at low speed would invite a tip stall.
2. For approach and landing you would have the flaps move in a convetional manner (down) and the ailerons would attend to roll. The flaps going down would in effect give you washout.
3. If you were really ambitious you could dial in some roll control with your elevators too.
This is the sort of thing that modern combat and civil aircraft do but they have sophisticated sensors and computers to handle all this for them. the civil guys do it to reduce fatigue and the combat guys do it more for the reasons that you are. It's one reason that the F18 shown here made it home missing most of one wing. Happens about twice a year, sometimes the damage is much worse.