Okay, let's see if the reply doesn't get eaten this time.
Cedric would make a great tech card, Bella is kind of useless as a Shaman card except against Hunters, Willow is a neat anti-mage Rogue card (that is Rogue, right?), Thunderwitch Lynn would go straight into a Handlock running Fizzlebang, easily.
Rose makes for a nice combo finisher, and feels mostly balanced, like Ancient Mage was in some older Freeze Mage variants. Zack is super duper OP, though. There's Stampeding Kodo, repeated board wipes, and Taunts that can deal with it. In Control Warrior, too stronk.
Batti and the Mirror are very much underpowered as Hunter cards, but no one cares about any Hunters that aren't Face, anyways ;3
Blue Rainbow, again basically a tech card. Mystery Theft, same. Princess Sparkle looks interesting as some kind of combo enabler for Priest. Automatically punch through any Taunts, Unstable Ghoul and even Elven Archer get more utility. Still sort of underwhelming, I'd say. Maybe if damage spells silenced, too.
Anyways, great work overall, looking forward to more stuff ^^