If you plan appropriately, you can enjoy the luxury of driving the speed limit with complete relaxation and be amazed at all the stress an anxiety surrounding you. Anyway, in short, I don't have a good answer for you. I don't think it is a major moral issue. Some would like to make it so. Concerning the paintball, I wouldn't worry too much.
Most kids can separate reality from fantasy.
You might be careful if you see someone going overboard after the games, but during the games, I would expect all the kids to get caught up in the good clean fun of paintball. Anyway, hope this was a little helpful. May God bless your ministry and life.