Copy/paste icons & icns using AppleScriptObjC

Question

I'm opening a new thread following this one to see what can be done with AppleScriptObjC.
As an Applescripter since 1992, it's my duty to learn this language.
My need is very simple on paper: copy an icon, icns or image file to paste it on a Finder item.
Running Mountain Lion 10.8.5, I'm still using Xcode 3.2.6 because I'm not familiar with AppleScriptObjC and I need to make and update several Applescript based applications for my work.
If I'm not wrong, it's impossible to have 2 versions of Xcode on the same startup disk.
Is it possible to write AppleScriptObjC scripts in Applescript Editor or even Script Debugger?
Red_menace, if you are here…

Answer 1

@Red_menace
Your project is a piece of art!
But I need time to read and undersatand everything.
It's not so hard. Just some things are obscure for me.
For example, I understand why you call current application's to get NSEvent's modifierFlags()
But why for NSImage's alloc's initWithContentsOfFile_??
@twtwtw
I made a Applet as you said and pasted in the following code.
No way to make it run.
I'm missing something. But what?
script iconTest
          property NSWorkspace : class "NSWorkspace"
          property NSImage : class "NSImage"
          on run
  -- first, an icns file
                    set filePath to "/Users/xxx/Desktop/iconChange/dossier sans titre 1"
                    set imagePath to "/Volumes/MacPro 2/xxx/Icones en cours/2013 icons by Factory/excel/excel-16.icns"
                    set image to NSImage's alloc's initWithContentsOfFile_(imagePath)
  NSWorkspace's sharedWorkspace()'s setIcon_forFile_options_(image, filePath, 0)
  -- second, a folder with custom icon
                    set filePath to "/Users/xxx/Desktop/iconChange/dossier sans titre 2"
                    set imagePath to "/Volumes/MacPro 2/xxx/Icones en cours/2013 icons by Factory/marques"
                    set image to NSWorkspace's sharedWorkspace's iconForFile_(imagePath)
  NSWorkspace's sharedWorkspace's setIcon_forFile_options_(image, filePath, 0)
          end run
end script