Thanks for the valueable help. The PDF was quite fruitful to read, gving me the impression C&C blends between 1st and 2nd Ed. AD&D rules. As said before it improves some aspects e.g. with the challenge levels and attribute rolls. I think I will give it a try!
Although I must try to navigate through the FG III software first, as I haven't found docs to read about it. I know there are video tutorials, but they vary widely all showing different versions, features and there seem to be quite some changes.
This would lead to another topic I assume, but probably this question has been raised many times and there's already a post on this subject ... somewhere ... ?