Yeah the servos are pretty typical RTF stuff... compared to better servos they are ( cough * crude * cough ).

However I doubt you'll have problems with them unless you are into heavy 3D stuff. A typical sport flyer will be fine with them.

As far as the Ailerons....

Take the horns off the servos and check the travel of both servos at full extremes.

Put a mark on the servo to assure that travel in each direction is equal.

Then adjust the linkages to equalize the movement, even if this is at the expense of maximum control surface movement.

I found that when you switch from one vendor's RX to another, the pulse widths affect how far the servos travel and where the servos center.