Translation of Defizienz

It actually happened to my cousin's youngest kid. He was repeatedly warned not to smoke in the courtyard of the school. At the end he found himself expelled from the school. It could have been an interesting experience for him though.
I met the company last autumn, because the site's traffic is getting pretty big and they invited me to a workshop. They have convinced me that I have to put their logo at the top of the page to maximize exposure and this was a big mistake.
Which region in Germany are you from? I live in Aarau in the state of Argau, that is in the middle of Switzerland not far from Zurich, Lake Zurich and near the border city of Basel.