Setting the idles and fuel/air ratio

Well I had the idle set way high to compensate before so it drove fine but the gas mileage was killing me. Thats why I adjusted it. I know the numbers are rough guages I just needed a start point and it worked out. So if I bring the idle up I do not need to worry about the fuel air?

My main concern was if I reset the idle with the headlights and ac on will my idle jump to high when they are off?