Propagation action how to list which account have them and how to alert if the action fails

You can configure the contact email for the managed system (if it’s a local managed account) or Domain Managed Account and Domain Managed System contact email. If the propagation action fails the contact email will receive an email notification for the failure action. 

To list out the accounts that have subscriber accounts there isn’t a report available today but this could be achieve by creating a smart rule. You can create a smart rule to link all these accounts together based on a unique name which service account would usually have or making use of user attributes.