If we restore the master Db with the help of a backup due to any corrupt or missing files, Are we going to have the user databases as consistent as they were before server shutdown? Or Do we have to restore them as well from available backups?
It depends, there are examples of situations that could occur. **Example:** If you recently added a datafile to a user database, then restore the master database to a point in time before you added the datafile to the user database. This datafile would be missing in sys.files. Same goes for logins and so on.