Yes. If it's an airsoft it will sting. If its a BB gun or pellet gun it can penetrate the skin and do damage to a person.
Yes they are fairly consistent
Co2 is for paintball guns. plants breath it in and expel oxygen
Not all pellet guns use C02 some are designed to use a spring or pump. Pellet guns that use C02 are rapid fire guns and do not require re-cocking or pumping between each shot. BUT they usually have less power that spring or pump pellet guns.
No. They also do not work on all guns interchangeably.
Most all C02 air guns use the common 12 gram C02 cartrage.
It requires a C02 bottle to hold the C02 and the gun must be made to accept the bottle. Most large sporting goods shops and paintball shops can fill the C02 bottle for you
No not all of them are spring. Some are also pump or C02
I assume you are asking about BB guns not Air soft guns. There are a few that fall under $50 but they are C02 not spring powered. Marksman makes a line of spring pistols under $50 but they are terrible and not worth the cost. See the link below for C02 air guns.
Your question is a oxymoron. Pneumatic BB guns are single shot. Machine guns are Multi shot. There are several C02 driven BB machine guns
No! they are powered bu Air or C02 that fires a Pellet or BB but NO gunpowder is involved. Hence they are called "air guns."
They are about the same, depending on the pistol. C02 has a tendency to be a little louder on certain pistols but not much difference.
A little harder but Yes they are. However spring powered air guns are usually stronger than C02 air powered guns. Spring powered guns are single shot and must be reloaded between shots where as C02 usually uses a clip with pellets or BB and is semi automatic. ( Generally speaking but not always)