If it is his/her first paintball gun then yes. There is no need to drop a ton of money on a gun if your kid won't use it after one play. If you are going to go spring, Spyders and Tippman are two reliable brands, and sell pretty inexpensive guns. If you find that they like it, upgrade to a spool valve gun (Ions, Dyes, and Protos).
A paintball gun
That sounds reasonable.
Spring.
Paintball is a $700 million dollar industry, that grows 25% each year.
Start out with a pump gun, learn proper shooting positions and the value of aiming.
No, you must be 11 to play paintball in the US.
Nope
In 1981.
Nerf toys of if you dare... a paintball gun.
Yes. Although all standard paintball guns shoot around the same distance, there are certain barrels or paintballs available that add range and/or accuracy to the marker. Besides that any marker with a longer barrel and optics could be considered a "sniper" marker.
spring or summer
22k a year