When I search for old questions, my fist place is the admin link for question bank http://moodle.somewhere/question/edit.php?cmid=...
There I find a list of questions.
But to find the old ones in a category is not easy.
please add: last-changed-date to the last-changed-name.
this should be an easy task in programming - but of I understand that this is not easy from organisational view point.
MAy be this is already a task that a theme changer could do?
I recommend also to add more filters: like changed before, or used more then once, but this is advanced stuff.
and plase explain this label: Also show old questions - how old?