Yes If you have body armor, WEAR IT!
And usually there is a disclaimer that is accepted by patrons of paintball places that implies the user can't hold the park/facility liable for personal damages/injuries.
Yes but not very bad. Its a stinging sensation that hurts for a few seconds, then quits. Like getting popped with a towel or something. Usually you will have welts or small bruises
It won't hurt too bad as long as you have a few layers on. I found that it stings more the moment you get shot and then it hurts if its touched the next few days.