while getting beyond the delay()-command within Arduino I came across the concept of the StateEngine as covered in several Tutorials. It allows for a sort of Multi-Tasking while leaving CPU-pwr for other tasks. A logical next step would be to write everything in OOP.
A LED&Key-Shield was lying around and there was intel online about its useage. I ended up using the LEDs as the eight engines which have completely independent states (on- and off-Times).
serves as an example.