I can thank most, if not all of my successes to either google searches or help from others, in another way. I feel obligated to add some of my learnings to this community for other answer seekers to find!
So regarding the filenames not being compatible with Windows and special characters such as umlaut. Did you create a modified version of the text.php file like described in this thread?
This seems fairly doable. I'm going to try it right now.
EDIT: so far the custom slugify function from mentioned thread seems to do the job. Super happy!