I definitely think you should be asking these questions in the Scripting forum: InDesign Scripting
I suspect you could create a startup script that would run in the background to watch for close events, but If ID is force quit, I don't know that it would be able to finish running and clear the recovery folder. I'm not at all convinced this would be a good idea anyway. Auto recovery is, to me at least, one of the most powerful and important features in ID, and one I need from time to time -- some files do occasionally crash, after all, and you don't want to automatically throw away something valuable that could be recovered. We even rely on it here on the forum when solving problems for users who find themselves unable to save a file for unknown reasons.
If you have users who routinely force quit, they need to be retrained. This is a USER problem, not a scripting problem.
