Want parent MENU_LOCAL_TASK tab to show when on a child page
You can do what you want, but you need to change the url structure a bit. If I understand you correctly:


control/jobs: List of all jobs, should be MENU_NORMAL_ITEM 
control/jobs/%node (You should have a load function for the job, if not a node than something else), should be MENU_NORMAL_ITEM
control/jobs/%node/view:  MENU_DEFAULT_LOCAL_TASK (doesn't have  a callback)
control/jobs/%node/download: The download page for a specific job, MENU_LOCAL_TASK
control/jobs/%node/settings: The settings page for a specific job, MENU_LOCAL_TASK


You can take a look at the node and user module to get an idea on how create tabs in Drupal