This is an interesting concept and a nice quick read for my lunch hour. :) And I think you've got Cas's thinking right. He reminds me of Sam, who thought demon blood was the only way to go and he was the only one who could do anything. Both were drunk on the power and chose the wrong path. I hope that Cas will be given a chance for redemption the same as Sam.
Many thanks for this, In some episodes Castiel says how his 'vessel' craved real food i.e a burger so I am guessing that somewhere within there is still Jimmy Novak.
Yes he is like Sam, I reckon that is how Dean see's him, and he forgave Sam eventually, so now we must wait until Sept 26th to see what comes next...so far away *sighs*
Quick reads are very handy sometimes :)