I'm building a pattern plane. Actually, it's going to be a modified Curari. My question is can I add flaps to the wing, which will be a fully symetrical airfoil. I've read that flaperons could cause an unstable condition by adding negative washout. So would flaps cause unstable conditions at low speed (landings)? The original Curari had a spoiler type flat setup which I want to eliminate and just go with the flaps. Also, the anhedral stablizer I would like to keep (looks cool). Does this have any unfavorable flight stabilities or positive flight characteristics?

Thanks