RE: 2 questions
The charging rate for your battery does not depend on the number of cells, but rather on the discharge rate of the battery. You should try no to exceed the discharge rate when charging your battery; therefore a 600mah battery should be charged at 0.6 amps or less; a 1000mah battery should be charged at 1.0 amps or less; etc.
I agree with AJ that it sounds like you are overcontrolling the plane. This is very common for beginners. make sure that your controls are attached to the outermost hole on the control horn. If this is still giving you problems, try moving the controls in by one hole on the servo arm.