Wow, Matthias, What a great analysis of three days of work! If you were to compare my two sections of this course (about 13-15 in each section) you would see that it has exploded exponentially in just a few days.
The two sections have dealt with the forum very differently. I had given both sections clear instructions to post ALL their contributions under the Week 1 header. One section complied very well, which lead to a VERY long thread of contributions. The other section has many individual headers: either they can't read and follow instructions or they instinctively tried to create a personal section structure. The result is very confusing since there is no way to relate contributions for one thread to another and there is no way for me as a teacher to move things to try to do some didactic "housekeeping."
Your contribution showed me how very complex our forum structure is (after only 3 days!) and why I feel the need so strongly for a better tool. Thanks for visualizing this for all of us.