Hi guys
For colleges such as ours we have rolling intakes. As a result there is never a time when a course can be resit to ground zero to delete all student files - there are always active students on a course, who come and go over time. This is why it was so useful in older versions of Moodle to be able to delete student submissions. Our tutors did this when they marked the file and uploaded a response file.
In terms of student records, we have a copy of the marked assessment on another server.
Doug, I have not used our current site (2.6.2) to delete files yet, but for the last 5 years I used 1.9.6 and deleted assessments them from the file repository with no issues. At times the software created empty folders for student assessments where I had deleted them, but I never had any errors arise.
Smiles, Laine