no
It may or may not depending on the type of replica.
It's a copy of a gun/rifle that can't fire.
dry fire it without any BB's
You don't do it any good.
yes
Non firing replica
You can, but excessive dry-firing causes wear on your gun and will break it earlier than usual
No, and you can't drive a car with no fuel. A gun is a device to launch ammunition. You can "dry fire" a gun with no ammo, but that is not good for SOME guns.
It is not a good practice to dry fire paintball markers, as it can give unnessicairy wear to the o-rings.
Try google
No, you do not.