I did have to add a bit of right and down thrust on my 4* 40 before I was happy with it. You must realize that there is a natural tendency to yaw and roll left due to torque and prop pitch, so if the engine is straight, or especially, if there is even a hint of left thrust built in, you will pull left like crazy.

I have the throws maxed out on my 4* 40 and it is very aerobatic. I love it. The roll rate (on high rates) is just fine. It will do a great flat spin also, right side up, and to the left, with about 1/3 throttle. It's awsome..... won't climb doing it though, but a nice slow, stalled decent. It takes max rudder and elevator inputs to do that too. IF your hinge line was built a bit too tight, you won't be able to get max throws. I think this is more important than sealing the hinge line. I leave a pin through the center of each hinge when glueing them in to get a nice even, and not too tight, hinge line.

Practice doing slow rolls also. That requires proper rudder inputs during the roll as well as elevator (using opposite rudder to keep the nose up) ..... and snap rolls using same direction deflection on rudder and aileron.

Ernie