This all depends on the country and location where you live. In the United States you must be 18 to purchase one. However to use one, that is up to your parents or guardian.
Different countries have different laws on pellet guns.
the proper size
No. A pellet gun would use compressed air.
Use C02 to propell the pellet
No. Even if it would fit in the chamber, there is no firing pin on a pellet gun.
Nope. Pellet guns are fairly safe to use.
I think you mean pellet gun. That is a gun that fires a small lead pellet but does not use gun powder. It uses compressed air or compressed gasses to push the pellet.
No
Use a .177 cleaning rod and push the pellet back out of the loading port.
You can't. You will have to sell your old air gun, then use the money towards a new PCP air rifle.
It can't use a regular cartridge, no.
In most states you must be 18 years old
Yes it does.