After reading through this excessive rhetoric, I have come to the conclusion:
Having a DELAY on an INSTANT CAST is completely retarded and results in the Warlock class degenerating to this. And by degenerating I mean that this thread reeks of hey I thought this was a video game and not another stastical analysis course. I mean, I enjoy using my neurons, but not when it's to improve my dps by 1-2% to workaround poor design.
The real question here is why Blizz makes an instant cast with a delay. Could you imagine if disc priests had to deal with an application delay on PW:Shield? The sky would fall.