Translation of Präzedenzfall

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.
There are changes in regulations for people who wish to travel to Eastern Europe. This is advantageous. In the U.S., as in every country in the world, there are positive and negative changes.
I am glad that you accepted my offer. I would like to write letters and emails in English and if you want you can write back to me in German. I want to correct your German and so we will both get better.