Hi Christian,
I set up a new role and I found all the FileSystem actions there in the list. Not exactly sure what they're doing, but documenting is a little later step (Yay!).
I added the FileBrowser, FileSystem_RW and Workbench_Content ones, and right now the CSV file creation is working as long as the users have my role associated with their username.
It's still Ok, because I did not want to make everyone a developer or an admin and see extended content while logging in directly to MII UI, while these "rights" are practically impossible to test for regular users without the functionality offered by an admin menu or the workbench.
Regards,
Paul.