Why not, if you are prone a lot, go ahead. If you run a lot, I wouldn't suggest it, they can get hot.
There should have been a battery and charger that came with it. (electric) I think you can buy a 7.2v battery and a charger at airsplat
in general 180 $ is the minimum for a reliable rifle.
A good brand of electric razor that leaves minimal cuts would be RazorSharp. I have used it for years and I believe it does a good job of getting your facial hair soft and smoothly.
soft clean cloth
Try oiling of the gearbox.
No. No license is required.
Most good air soft airguns have a metal spring, gears and gearbox. The rest of the gun is plastic with an electric motor.
It has to be electric (AEG).
If you rifle is a slide action repeater (pump rifle) these DO have a collector's value. It will be based strongly on the condition of the rifle. It could vary from $250 up to $800 for VERY good condition. Strongly suggest you not attempt to "clean up" the rifle other than a wipedown with a soft oily cloth. You WOULD need a hands-on appraisal.
Most guns come in black.
look around on Amazon.com
Contact the maker to see if it is possible and what it will cost.