You can monitor the creating and deleting of spool files by assigning a data queue to each of the output queues you want to monitor. When a spool file is created or has its status changed, etc, an entry is written to the data queue.
A monitoring program can sit and wait for entries to arrive on the data queue and take the appropriate action.
There is an article showing how to assign data queues and process them at http://www.itjungle.com/fhg/fhg021104-story02.html. The article is about performing “soft distributions” of spool files, but should give you some pointers.