Bring them on. They can be a show all by themselves at time. As far as line cutting, i believe this happens all the time and is not a South American issue. I am 6' 4" and 230 pounds and in line a grab a rail with each hand and no one is getting by. They will sometimes point up ahead and unless i see thier group up ahead and think they can make it to them before they board the ride, they do not pass. I just tell them looks like you will just have to wait your turn.
Best way to stop line cutting is to grab the rails and stand your ground.