I dont think backing up my data through samsung kies backs up android kitkat
Someone else will have to tell you what you will have to go through to return to KitKat.
But the answer to your question is "NO you cannot backup KitKat through Samsung Kies."
I've been running Lollipop for about 7 weeks now and I would advise you to stay with KitKat!
(Unless you really like White backgrounds & Teal) I would hold off if you can until "M" is released!
Too many problems with Lollipop and I don't think it really offers much! (Just my opinion!)
Sent from my Galaxy Note 3 "Size Does Matter!"