Im talking about the row of useful buttons that use to sit above the code editing area, like adding / removing comments and checking your code.
Would anyone know how to get them back?
The Action Toolbox is dropped in Flash Pro CC.
You can add remove comments using the keyboard shortcuts.
Where can I learn about Flash CC keyboard shortcuts?
Comment : Ctrl+M
Once you open an script you can see these shortcuts in the edit menu. The Edit\Keyboard Shorcuts Panel has the list of all predefined shorcuts for Flash Pro.