thank you. I finally found my files.
When I open a (Windows)text file, at the end of each line there is a mark for the CR-Byte.
My suggestion: an item in "options" for selecting Windows/Unix(and perhaps Mac)ending.
Perhaps in addition a selection for showing only the "mnt" files and folders, like the "library".
I still have the problem as mentioned under 2. and 3. that continuous writing is not possible.
Is that a malfunction of my device?