Got something working
using pngshow (found on this site, part of screensaver), the images from the original link and some ugly modifications to the scripts.
Since I didn't find a cron for kobo and rctwake is/was a bit too hard for me this time, I just threw it in a loop with a 30s sleep.
Didn't care for the quiz, so I always display with credits
Still if anyone comes up with a nice implementation, I'm always intrested