No. There are no urban areas that allow paintball.
Yes, all brand paintball guns use a tank or other source of pressure.
Generally it is bad to leave batteries in anything battery operated for long periods of time. I have ruined more than one useful thing because I left batteries in until they started to corrode. In the case of paintball guns, leaving batteries in is essentially the same as leaving a low grade weapon around for anyone to use or misuse. You can do damage with an improperly handled paintball gun.
Not completely sure how you could use a balloon instead of a paintball marker. Though paintball is known for its guns therefore no.
Nearly everything. Paintball guns are fired through the use of air or CO2. Also they shoot only paint. bb Guns shoot pellets, and look completely different then most paintball guns.
If you aren't mature enough to play paintball, you aren't mature enough to use firearms. There is no way you can confuse paintball or vidoegames or airsoft for what you should be doing with actual guns, unless you are not old enough to use guns.
Paintball guns are not classified by their roles. If you ask the ref if you can use two guns that's fine. Having two guns (with basically the same range) is a waste and will slow you down.
No, you should use only paintball specific of air tool lubricant.
the guns don't use batteries.
Most paintball guns use an above hopper instead of magazines or clips like firearms. The standard hopper holds 200 rounds. Most magazines for paintball sim-markers are 30 rounds. No paintball guns use clips.
It is like paintball mixed with laser tag. Same rules as laser tag but you use paintball guns with rubber ammo.
Yes, infact it is recommended.