Does CO2 laser help with keloids on the body and scars that dip inwards?

Can cO2 laser be used on body parts that are not face/chest/and neck, like full back/butt/legs as well as stomach/breast&all that? I hear that it can kill precancerous skin cells as well as getting rid of sun damage&age spots? Does it help fully get rid of deep scars&keloids as well boost up sagging skin&increase collagen long term? Should you get a cO2 laser resurfacing treatment done every 5-10 years to help keep up since it does last years if done right in one treatment?