von Ken Task.
I don't know what you mean by some postings!!!
It appears you are admin of the moodle or you wouldn't be able to change recyclebin settings.
And the courses with issues are yours ... are there other teachers/courses in the system?
Again, looking for bulk that doesn't exist in the GUI could be performed via backend or cli mysql client access IF .... IF ... one knows exactly what they are doing and the ramifications those actions might have on the entire question bank for all teachers!
I'll say it again ... get mysqltuner.pl installed and run. Tweak settings.
'SoS', Ken