I could be nice to have more control over how strong the shadows are.
You do actually have a lot of control over that You could look at the "sun brightness" setting under the atmosphere tap, along with the shadow sharpness. another good trick i often use is to increase the cloud density, and move the clouds to a position where they partly blocks out the sun. this actually gives you quite fine control over the amount of shadows in the scene!
You could also take full control, and turn the sun off completely and rebuilding the lighting artificially. here is a great tutorial for interior lighting, made by Vlad Moldovan:
Thanks man, I will have a look on that.