Hello there,
I'm a software engineer from the UK and have extensive experience.
XSLT isn't really used anymore ; and XML to CSV conversion tools are plentiful. I provide XML --> CSV (and reverse) convertor tools for Windows and Linux, and develop one for you, within 24 hours.
It will take your specified XML file as input and output a CSV file, as per your EXACT specification (example files posted).
If interested, do let me know.
Cheers