RE: cub ground roll
Great advise from the other guys, but I would like to add one other thing. Are you using your low rates or high rates while taking off and landing? Do you have any expo programmed into your elevator, rudder, and ailerons? Check your throws and set the low rates to what the manufacturer suggests.
I have a Hanger 9 40 size Cub with a Saito 80 and 9 times out of 10 I take off and land with the low rates on. They are set to what Hanger 9 suggest. When landing; once the landing gear has touched down; I can almost give it full up elevator and it will roll out nicely without leaving the ground (engine at idle). You still have to be careful with the rudder though. Like the others have said; it doesn't take much to turn these planes. Might help you a little.
When I first got the plane; I was a little nervous on the take off and landings. Now that I am comfortable with the plane and know its' little kwirks; I love it. Just my 2 cents.