One of the great things about AGO is the ability to quickly add and change items...but this is also a danger. It's very easy for a user to delete services, maps, apps, etc. on which they spent hours working and are perhaps required to do business. With one click of a button, a well-intentioned user could bring business to a grinding halt, with no recovery option except to re-create or re-register. This makes using AGO as a production environment concerning.
Building off the Deleting an ArcGIS Online Feature Service idea, I would take it one step further and suggest that when items are deleted, not only are decencies listed, but that they also go to a master Recycle Bin area within AGO. Maybe this is a default AGO group to which only admins have access, and the admins can configure how many days items stay in the Recycle Bin.