Although I am not 100% certain, I believe there are little to no restrictions beyond common sense.
If you use your gun to threaten anybody, that's illegal. If you shoot non-participants, that's assault. If you carry it down the street and somebody freaks out, you could be stopped by police or possibly arrested. Just play on private property and don't be stupid and you should be good.
The Australian Book of Laws
It depends on the laws of your area.
No There is not
It depends on which field you are talking about.
Vagrancy laws in indiana
Indiana Department of Natural Resources.
It depends on where your backyard is. If it's your backyard and you are in a rural area, you should be OK. But if you are in a less rural area, there may be laws against discharging projectile weapons like BB guns, arrows, and paintball guns.
it would be unwise to have paintball loaded and the gas tank in. If would give the wrong impression if cops stopped you. But there are no laws stating you can't, as long as you are over 18.
There are no set laws for paintball in states, there are however country laws. Usually they are more towards common sense. If you are located in a rural area, away from the public, you are more then welcome to shoot paintballs. Though if you live in an urban area, this could pose a problem seeing as you are near the public with lack of protection for them.
No. The Indiana court would apply Indiana law.
Not in general but if u get caught u probably get in trouble.
Anti deficiency laws are laws in a state that prohibits lenders from suing borrowers for deficiencies. In Indiana there are conditions that allow for Judgements to be issued.