This is one idea I don't agree with. The way I always saw it, the sith eyes were something that developed from years of corruption by the darkside. Not something that suddenly appears due to the character's mood.

Same goes for Palpatine's Halloween mask features. I don't agree with that either. The first time we should see prune faced palps is ESB if possible.

Edit: Having said that, it DOES make Anakin's fall seem more believable and less of a conscious decision. You can see he's giving in to his hate, rather than making a conscious decision to do bad things.

So basically, I'm on the fence. Your way works a LOT better than the original though :)