If there would be a configurable 'Edit script' function in the Hollywood GUI the My Projects list would have been more sense. It should let to set up a command line which invokes the user's favourite editor.
Well, the problem is that there's already an "Edit" button to edit the properties of your own script. Adding another "Edit" button might be confusing and bloat the layout.
What about a new item in the Edit window where the user can define what to do when doubleclicking in the script list.
It could be "Display script", "Launch Editor".
It's implemented now. The "Edit" button now opens the project in a text editor. For editing the project properties, I've added a separate menu item. Default viewer and editor are also user-configurable now.