Status code of 1000 typically has meant the backup has reached the end of the backup plan an was success. 800 could mean it finished early or failed to finish at that stage in the plan?
The user id seen in that table (id 2) indicates the admin user ... first user created when the site was first installed and would be the user shown on automated backups. Do you have automated backups turned on and running?
Search mdl_file table for component backup.
select * from `mdl_files` where `component` like "backup"
See any with 'activity' under filearea column of search above?
Now some questions/suggestions ... higher versions of moodle now have a recyclebin ... a module/activity in a course is deleted and for X days it gets tagged as being in recyclebin ... which isn't the trash.
Those directories in moodledata/temp/backup/ ... shouldn't remain ... if cron job is running correctly that area is to be "cleaned up" (folders/files removed) if they are not involved in something like a backup/restore by a task in the overall cron job. Check your task list to see if there is anything failing.
If you have a tool to browse files or can ssh into server and get to moodledata/temp/backup/ inspect what's in the contenthash named directories ... .xml file are like roadmaps and could give you a clue/hint.
So ... sorry ... can't give you specifics and a true answer ... just some things to checkout/look @!
'SoS', Ken