Joey,
the proportional adjustment is for when the heli keeps spinning clockwise or counterclockwise in an uncontrolled manner,the gain is for the gyro sensitivity if the tail wags side to side adjust the gain accordingly.Adjust the trims on the tx first for adjustments then resort to the adjustments on the 4n1.also make sure the swash is level then make fine adjustments from the tx.If you need to adjust the 4n1 be sure to disconnect then reconnect the battery after adjustments