Occlumency & Unforgiveable Curses

[septima66]

I've been contemplating this for a while now. Would knowing occlumency increase someones chances of performing unforgivable curses? We know from Bellatrix that anger, rage, etc... won't work. That you have to actually mean the curse for it to happen. Everyone has dark feelings inside of them, including Harry. If Harry didn't have these feelings then the very act of even attempting to do an unforgivable wouldn't enter his mind, yet we've seen him try 3 times, once on Bellatrix and twice on Snape. Now if you knew occlumency, could you block off all the good inside of you and leave only the dark accessible? And if so, would blocking off the good enable you to perform an unforgivable? You would essentially be blocking off any moral values you have, any doubts, anything really that would prevent you from committing an unspeakable act. Would the unblocked darkness be enough to give you the power to cast something like the Killing Curse? I've been wondering about this because while I am convinced that Snape is not evil, I've been wondering how he was able to perform the Killing Curse on Dumbledore. And I really do believe it was the Killing Curse, although I have to admit I've never seen the Killing Curse described as throwing someone bodily into the air. If I remember properly, when Wormtail killed Cedric, didn't Cedric just fall where he was standing? I guess that is something to consider...

Anyways, we know Snape is an occlumens - a superb one according to Remus. Could that be how he was able to perform the Killing Curse on Dumbledore? (Could that have been how Dumbledore killed Grindewald?)

As you can see I'm just rambling. I've been thinking more and more about a lot of small things as the arrival of DH gets closer.