No. If you move the directory to a existing directory, all files are just added. The string:
M:\Heerschende Data\MP3''s\%artist%
does not create a directory with the album name in it.
true.
As I said, files are overwriten (with a warning message) if you move the directory with Mp3Tag.
As I said, it workes here at my side. Experiment a little bit. I think you must doing something wrong at some point. Or download the latest version of Mp3Tag, maybe there is was a bug which is fixe now. Your status says you are still using 2.45b.