I think if Sylar eats or otherwise destroys Claire's brain, she's dead. A stick through the brain put her into suspended animation until it was removed.

On the other hand, she regenerates pretty quick. Maybe it comes down to how fast he eats...

Regarding English in India, I'm afraid that the reason is that the actor playing Mohinder only speaks English.

Ah -- I was wondering if it was something mundane like that.