Yes it was pretty awesome, I've rewatched the video a couple times and giggled. No fear of doing it again though, the budget really didn't include the ride but I knew I had to scratch it off the bucket list.
For the school they had a section cordoned off starting above turn 3 and just past turn 7. On this map you can see where we cut across the track, I'll eventually post a video and you'll see why they called it 'Little monaco'. So we basically ran down the hill towards 5 and up to 7. For those little cars it was more than enough to get a feel and run them close to the edge, although the track is a bit large for them and it was hard to get in too much trouble. I did almost dump it once at the top of 7 when i downshifted a bit too aggressively, but in the corners there was lots of grip.
They run a few different schools in different sectors of the course.
For the Nordschliefe they were doing the taxi rides and tourist drives (people with their own cars paying by the lap to go drive the course) so it was completely segregated from the new F1 course. 25 euro per lap plus any damages you do to the track and tow fees if they have to remove you. Also if you get into it with another driver one of you has to pay damages to the other, and there's actually some insurance policies that cover it, and if you can't agree the cops will be called and it will be treated as a traffic accident!
My rental car policy wont allow me to take it on track which is probably a good thing.