Well, there are different kinds of educational "events" you can go to. But they are not all compulsory. Most of the time you only need to sit the exam and pass. But in many cases you NEED to attend to scrape a pass. I think we've got a different concept here..
There are lectures, which are "lessons" following the (in my opinion stupid) method of frontal education. There is a professor standing in the middle of an auditorium, filled with (at some German unis, such as the LMU) up to 500 students, and talking about things, whilst YOUR job is to sit and listen and take notes.. they often conclude in exams.
The proseminars are mainly for first years because you learn about the methodology and such like of your course. They end with an essay and a presentation.
Then there are seminars, which serve the purpose to go "deeper" into a "special topic" in groups of 10-20 students. And here you actually learn something new. They conclude in you writing an essay and holding a presentation.
Additionally, there are "project seminars" in which you do research of your own into a topic you may choose out of a selection.
Sadly, I don't seem to be able to find an English course overview. Otherwise I'd copy you a link.
And as for the fact that your supervisions seem to be geared more towards making everyone understand than anything else: it probably is that way because each university student in the UK spends a lot of money on her/his education. If the course were so hard that the student would not cope anymore (as very often is the case here! In fact that even is the strategy of the unis here: they want to make sure that their students really want to do what they are doing and don't just study their subject because they follow a whim or because they want the academic prestige. Which is why they are "sieved out" by overly harsh exams, courses, projects in the first few semesters. So yes, many German students fail.), the student would have to stop studying and thus the uni would lose money.
I found it extremely weird that all international applicants at the uni of edinburgh received an offer - well all of them would have paid the largest sum for their education.... maybe that is not the explanation for that phenomena, correct me if I'm wrong. =)
And contact hours vary from "event" to "event".. each "event" leads to a certain number of "credit points" (either 3, 4, 5, 6, 8 or 9 for my course). Most of the time one "event" takes up 2-4 hours a week, and apart from some "events" which are compulsory, you may pick the others freely. The only criteria you need to fulfill is that you need to have filled 180 credit points at the end of your education, according to plan three years, but many students don't manage to meet this set time limit. A good friend of mine added another year because he was interested in too much to be able to cover everything within the time an average student is allocated.