I was a bit creative today.
In Calibre, I created a new library on the "extsd" on my Tolino. Now I can copy books from Calibré to that to that library on my reader.
Then I activated "automount" in windows so the Tolino should always get the same driveletter.
For now, this seems to work alright and it is a decent workaround for my problem.
I'm happy, My wife is even happier...
Any suggestions on solving the USB problem are still welcome.