When you first created the model type and selected the 2-aileron, 2-elevator model, the transmitter automatically set the second elevator channel to work off of the elevator stick and set the second aileron channel to work off of the aileron stick. Same for the trims. You only need to set up a single AFR for each FUNCTION. Please note that the elevator FUNCTION controls two CHANNELS, and the same for the ailerons. AFR is "Adustable Function Rate", and governs the function.