On the Eye: Is it possible, that like the Console Rooms, the Tardis has cataloged a future upgrade of herself and is now using/taping into it for power? If she can catalog Console Rooms that haven't happened, what says she can't do it for other necessary parts? Or maybe when she rebooted after 10's regeneration she decided to give herself an upgrade.
On the Infinite Tardis: She can be both finite and infinite. She can have a "X" mass, but since she can exist all time and space at once and duplicate and shift rooms at will and then shift them between time/dimensions, it would be true that from a certain perspective she's finite, but at the same moment she infinite.