Sort Github apps by updated time

From Github-Docs, it is clear that we can get the updated apps by since parameter in query. But few things are unclear in the doc.

  1. How can we sort the api result in Ascending or descending order? (no documentation regarding sorting direction)
  2. What the outdated parameter used for in the query (in mentioned doc)?
  3. Is there any Api or Github hook to know when someone deletes the installed app?