First of all, you are going to school to learn how to deal with situations like that. Also know that if you are going to a school with a big theatre department you will be working up the chain from the bottom, and you will have plenty of time to see how crews are run and how SMs handle all sorts of situations.
I think though that it is not such a great attitude to say that people who can't get it right in the first couple tries are "like foreign people." In the professional world it is not uncommon to spend many hours teching aspects of a show. When you have lots of moving scenery, flying scenery, props and actors that have to get on and off stage it can take a lot of time to get it right. Then try throwing in a costume quick change.
I suppose the point of all of my rambling is that as a SM you need to be able to get things to run smooth, but you have to be patient and be able to work with people. OYu can walk into a venue and have a completely veteran crew who can get everything done without you even telling people what you need, or you can walk in to a completely green crew who have to be taught everything, and you have to be able to deal with that in a civil, calm, and efficient manner.
I'm not so much worried about people messing up in the first couple tries -- but the scenario described, where the stage crew was unaware of where the scenic pieces went by the day of the show, that really does just strike me as foreign. I'm perfectly used to dealing with a "green" crew, but one way or another they're going to learn the changes before the curtain goes up. Whether that takes two rehearsals or twenty is dependent on the experience of the crew, but if it takes twenty rehearsals, that's what needs to happen.