Hey, I am sorry I don't have an answer to your first question. They all speak German and stay in Berlin for work after graduation. But I know Hertie provides german courses for foreign students, so perhaps that would help you with getting an internship in Berlin. I also did some research about the exchange programmes offered by Hertie and you can apply for that after completing your first semester. Is Hertie your top choice btw? If you don't mind me asking, what are your other options?