Many thanks to you all. I am overwhelmed by the positiv feedback here. I hope to be able to work on a new map soon, with an all new Brush-Set.

@Diamond:
I think I could create Brushes and Map-Elements and I could give you the informations of the Setting and the form of the Landmass, the actual rendering of the map and putting the informations into form would be your side. 1 Map my Setting, one Map your setting? How do you like the idea?