Nah, the Yata Mirror was said to be able to render every attack useless, and was stated to make Itachi completely invincible. As Owarij pointed out, it can change it's properties, meaning that it can deflect anything thrown at it, even combined elemental attacks. The Yata Mirror doesn't necessarily need to transform into an element, it can transform into close to anything. An example would be, if Kakuzu throws an attack from the Fire and Wind mask at him. In that situation, the Yata would turn into something like, for example, diamond, which would successfully counter the incoming combinations of attacks. It wasn't said to make Itachi invincible without a reason.
Not looking into the eyes of an enemy is easier said than done. Unless you've specifically trained for it in the past, you won't be able to hold your own for too long without looking into the eyes of the user. Both the Raikage and Killer Bee had had multiple fight against Konoha (And therefore the Uchiha), yet both of them were caught in a Genjutsu by an Uchiha, simply because that's something Uchiha specialize in, using the chance to get to the opponent.
Itachi may need to charge up for the Amaterasu, but it doesn't mean that it would give Kakuzu an opening. Like I stated in one of my posts above, if Itachi is pushed far enough to use the Amaterasu, he'd already have put up the Susano'o (Which is further supported by the fact that he knows that he'd be vulnerable while charging up if he doesn't), meaning that neither Kakuzu nor the hearts would manage to get through.
The mask strategy would also not work, simply because Kakuzu is not aware of the Amaterasu. He'd have no reason to go on the defensive side when he sees Itachi closing his eyes and bleeding, because of lack of info on the Amaterasu itself. He wouldn't be aware of the fact that Itachi can make a flame appear on him until the attack has actually been cast, and by then, he'll already have lost.
