Really great job with the op, and its nice to have an organised collection of all quotes and speculation.
Anyway, my predictions are;
- Flight mechanic used, though somewhat limited and not like the game takes place totally in the sky.
- Artwork girl operates as the sword, and as a context sensitive item. You unlock 'powers' for her, and she transforms into the right item or object at the right time, as a means of streamlining the item selection menu.
- MotionPlus pretty heavily used for most everything in the game. 'Duels' with some enemies require precise swordplay, like a puzzle.
- Vitality Sensor used in a similar way to the N64 Rumble Pack in Ocarina of Time, and the GBA link cable in Wind Waker. It does something, but is not essential to the core design and works as more of an extra.
- Graphical style basically the same as Twilight Princess with the benefit of additional hardware power.