RE: Flaps or flaperons?
Donate the old Cub to a new club member to help him get started and them mount that 91FX in a plane that will fly the way you want, not "boring scale-flying". Why do people insist on hacking up a perfectly good basic airplane to try make it do things it was never designed to do. Start with the right airframe for the performance you want and you'll get the style of flying you are looking for without compromise.
As to your flaperon question, I DO use them on my E-Flite 450 size Taylorcraft on floats. It has a good combination of thrust and light weight and the slight droop of the flaperons give the clipped wing some added stability/lift for takeoff and landing. As soon as it's off the water at a safe altitude, I retract the flaperons and it is fully aerobatic...even with floats.
Jaybird