Nothing to be afraid of with 3 channel planes. They don't roll the same as an aileron equipped ship,
but they fly fine. In fact, some electric trainers, like the GWS Estarter, can be turned with rudder or elevator/aileron. I know this as fact, because my Estarter aileron servo came loose one day while it was in the air, and it was a nonevent because of the way it handles with rudder only.
And friction fitting servos, even if secured with sandpaper on both contact surfaces, is not a good idea.