This is a feature that Xenforo, Burning Board, Flarum and NodeBB offers. They allow users to quote a selected piece of text instead of whole post. Users can simple select the text in a post they intend to quote and they get a tool tip to insert it as a quote. Something that will be a nice addition to Elk as well, in my opinion .
You mean quick quote:
http://www.ElkArte.net/community/index.php?topic=3456
Yes. The same.
SMF is a thousand light years behind other scripts in terms of ideas.
x-ref http://www.elkarte.net/community/index.php?topic=4040.0