Thanks to all :-)
In any case, I made the first experience with "nodes". With my previous habit from TG classic, to program all surfaces on "surface layer" and "child layer" from top to bottom, I couldn't continue in TG3 especially with the objects. Funny thing was, that I only found a (youtube-) tutorial for limiting areas of e.g. trees via nodes (pop obj > density shader). All my instinctive attempts to program it via the object panel had failed...

so I did my first step towards the node panel

And now I do one step after the other, when I need new knowledge.
I hope that my currently running animation calculation is finished soon, so that I can continue my lessons.
I have started with this in TG Classic: frame0165_1.jpg
...and something similar to this should appear sometime in the future in HD: temp.0042.jpg
Here is just a "not listed" link to youtube to see, what's the plan:
http://youtu.be/8JQqUKf3CUc(The computationally complex parts rendered in 500x250 and all aggregated with magix to get a rough scene running.)
At the moment a 800x450 750 frames test calculation for the sunrise runs. After that I will see if I have learned my lesson in avoiding flickering of shadows and atmosphere

and I will start to give the balloons above the canyon some movement and rotation.... then some pebbles at the riverside... and and and...
So much to do. But I hope that there still remains time for one or the other nice scene image.