I'm not sure on the launcher with the lowest resources used, but if you want to add homescreens to the stock launcher,just pinch with 2 fingers and it will show a blank with a plus sign. Tap that and it will give you another screen.
I personally use next launcher, but I'm pretty sure it is not very light on the resources. I got it when they had it 40% off (still is expensive though). I enjoy it, but you're right on the commercializing of the go launcher stuff.
Sent from my LG-E980 using xda app-developers app