RE: citabria
WARNING: I have not built or flown this kit myself, but I asked the same questions you did, and here is what I was told.
Scale Citabrias have a tendency to perform unwanted snap rolls, due to the short tail moment. This tendency can be tamed as follows:
*Keep the Center of Gravity well forward
*If you have a computer radio, set the ailerons up so that you have at least 60% upward motion, 40% downward. 70/30 is even better.
*When building, set the ailerons so that, when in "neutral", both ailerons have a few millimeters upward deflection. This creates a washout-like effect.
Once set up properly, the plane flies well. Supposedly the Citabria does not have the best ground handling, but reports vary and I don't know of any way to fix this.