How can I simplify the use of flags with Views Bulk Operations?
Instead of using the "Flag (or unflag) a node" action directly, create new a rules component and show it in your administrative view.


Navigate to Configuration » Workflow » Rules » Components
Click on Add new component , choose Rule from the components plugin drop-down menu.
Choose a name (e.g. Approve), add a parameter with the type node.
Add a condition, choose Node is flagged from the drop-down menu.
Choose the appropriate flag, select the node-parameter for the node, choose site:current-user for the user on whose behalf the flagging-action will be performed, select negate such that the condition will evaluate to true when the node is not flagged.
Add an action, choose Flag a node from the drop-down menu.
Choose the appropriate flag, select the node-parameter for the node, choose site:current-user for the user on whose behalf the flagging-action will be performed.


Edit your administrative view, configure bulk operations such that the Approve operation is shown instead of the Flag (or unflag) a node