1. Yes,It is normal beaviour of software that SQL Db is not deleted when a vault view is deleted or software is uninstalled.This actually comes in handy in case a vault is accidently deleted.(That may not be the developers intention )
2. If database is accessible,one can restore it and will get access to full epdm except Actual Files.This include Worflows,Logins,Cards basically everything you see in Admin INterface.
3. Uninstall,Delete Dbs,Delet Registry from
same from HKEY MACHINE