I'd agree with Jim that you should start with a much more simple profile type but one with flaps so you can experiment. With the linkages on the outside it's easy to change the ratios and see what affect it has.
A stunter without flaps can be made to turn a very sharp corner but sharp corners rely on a very light wing loading or it can stall. Flaps change the camber to give more lift to carry the G loadings but have two bad affects. They add drag which slows the model down exactly when you don't want it to slow down and they give a pitching moment working against the elevator so the load at the handle is higher. But because virtually any flapless stunter can be made to stall the advantage of flaps far outweighs these disadvantages. They do add one more aspect to trimming though in that both flaps have to work equally or the model will roll slightly especially in hard turns.
One of the big mistakes that's usually made is to have too much flap movement. The old style was a 1:1 ratio but with the longer tail moments in more modern designs less flap is required. Less flap means less drag so speed is maintained through corners better. That's where adjustable controls and trial and error come into it. On my stunters I use a ratio of about 3.5:1 so the flaps only move 5 degrees either way but it's got a very light wing loading.
As for landing, they make a huge difference. You can land reasonably fast with neutral controls on the main wheels or extend the glide a little for a 3 pointer. Or do what I did once, keep gently feeding in up as it slowed and touch down on the tail wheel with the mains well above the ground at not much more than a fast walking pace...not in a competition though
