@Umbralux: Yes of course this would be the ideal solution, if there wouldnīt be a lot of grey areas. From my point of view it isnīt a clear choice, neither for the player nor the GM. I agree that some dice rolls, which decide if you are morally rotten or not are not very elegant. My houserule was more or less some kind of brainstorming. It bothers me a little bit that there is no inbetween for lawbreaking.
For example:
When Harry makes a soulgaze with Molly after he finds out that she has brainwashed her drug addicted friends, he sees that she is not totally stained and can be resued
I would like to simulate this rulewise: There are things that are not really lawbreaking according to the letter of the law, but the should have a small impact on the soul of the wizard.
@Richard Chilton: Yes the white council doesnīt bother. But how cruel is it to force a feeling, intelligent being to fullfill you every wish. When you use magic for this, it should be some kind of "lesser lawbreaking", donīt you think?