I have nothing specified in the application section of the behaviour (i.e. the bit where you can drag and drop an application into).

Instead I just execute some AppleScript (which launches and monitors Safari for my purposes) via a shell call to osascript in a 'Launch Safari' action that I created and assigned to the 'Activated' event for the behaviour.

I could probably bundle my AppleScript into an application using Automator and then drag it across and maybe then it would work, but that would mean that whenever I wanted to adjust my script I'd have to rebuild the app (or edit the contents of the bundle directly). Also, I pass command line arguments into the script, since I may want to use it in multiple contexts/behaviours and this is nice and easy using the method I have chosen.

Anyway, not a big deal really since I used the global switch to make behaviours 'stick' or I could use the method you suggest. Presumably if I set this sticky behaviour using AppleScript like you say then when the behaviour is activated then it stays until the behaviour is manually deactivated does it? I.e. I wouldn't need to explicitly turn it off with another AppleScript call or something?