I have completely forgotten and overlooked Fain's ability to corrupt someone. I think you are correct he corrupted Egwene, however subtle. This might explain some of her thinking to herself later in the series where she doesn't want to think ill of Rand. She is mentally attempting to resist the Fain programming. That being said, it does not excuse the rest of her personality. I have know several women with an overlarge share of Egwene traits, and it ain't pretty.