1/. IPS does not support File events indeed, but it supports Schedule events that will suit your purpose well. Check How to schedule Information Steward task to run after Data Services job is completed? - Enterprise Information Managemen… for the right approach.
2/. Many of my customers use a "file watching" mechanism to sync DS jobs. Triggering jobs create a file (using exec built-in function) in a termination script. Triggered jobs wait for the file to be created in a startup script (file_exists of wait_for_file built-in functions).