admins probably requested cause those provided info about your site they felt un-comfortable with ... although, I don't know why. Messages have already been distributed so removing images won't fix that! Besides, your moodle is on the internet ... your admins might be surprised as to how much poking and probing is already going on!
One more thing about my suggestion to change assignments ... more like a warning if you are in a space crunch. Depending upon your version of Moodle you have recyclebin. An assignment deleted from a course (the video submissions) will undergo a backup of those deleted assignments ... thus you won't see immediate relief from space crunch - rather the opposite ... an increase for those deleted assignments backups.
Before you do that ... if you do that ... check out the settings for recyclebin and set the recyclebin link in the course admin menu to show all the time and more importantly, reduce the time to retain those deletion/backups to lowest. Reason, cron job will move those backups to trashdir more quickly where one can (in a space crunch) manually remove anything in trashdir.
You've got some work to do!
'SoS', Ken