RE: Is it hard to fly a Cub?
Cubs can be a bit on the twitchy side on take off due to the relatively narrow and tall gear. If there is little to no cross wind, you shouldn't have much trouble as long as you are gentle with the rudder. Do a few practice taxi's up and down the run way to get the feel for it. When you're ready to take off, roll the throttle on gently. With the Cub, you will be able to take off easily at 1/2 throttle but make sure the model is ready to fly before you pull it off the ground. A Cub will tip stall as easy as a heavy war bird if you get heavy fisted while flying slow.
In the air, a Cub is an easy flying model though they do have a few quirks about them. Unless you setup the ailerons with quite a bit of differential throw, more up than down, the model will tend to skid through turns. You can get around this with either co-ordinated rudder, or the aforementioned differential aileron throw.
Landing is cake, but if you land too fast on a rough or grass field, you could end up flipping the model on it's back during a nose over.
John