Real simple- this shows paintball in an unfavorable light, you sense this and are uncomfortable with it. Listen to your conscience. If you can't modify the plan to make it safe/ portray paintball fairly, don't do it. It is a bad idea.
If your softball team were asked to hit some shmo in a "big prices" costume with a bat, it would be bad. Same thing except that softball is accepted and in no danger of losing legality.
If your boss doesn't care about your concerns enough to alter his notion for this comercial, you have a real problem.