The models were changed to reduce overheads and keep gear more uniform across each race. They pretty much said this won't be changing, so don't bother getting your hopes up. As for hair clipping, that's pretty impossible. They'd either have to animate hair based on every piece of equipment in the game, or restrict hairstyles to shorter lengths which won't clip in the first place.

Come on guys, think about this logistically; there's never been a game made that didn't suffer from some clipping somewhere. Certainly not a game which allows you to customise your character to this extent.