This is a useful property of a feed, which unfortunately is set to OFF for a newly created/imported feed.
Is there any way to:
Will the developers consider adding these features?
No, this was done deliberately (OFF). Long to explain.
How about the second part of my question:
An option to set this property for multiple feeds?
About second part... You can create issue at https://code.google.com/p/quite-rss/issues/list