thank you for the answer !
This seems to be a professional but quite work intense solution
My current approach to solve this problem is the usage of only dynamic light.
The problem with shadow casting which stopped me from using dynamic light is solvable/reducable through positioning lights at the positions where a shadow should be casted but isn't - these lights need to have the negative value in red/blue/green of the original light to eliminate it's effect.
But as this is a quite poor workaround I'm still searching for an easy approach to solve this problem.
Cheers