Hi, thanks for replying.
You make some good points. I realise priest has some of the best board clears in the game. But i have two problems with Auchenai+circle, 1) it is a combo that you need to draw early (sometimes by turn 4) which makes it quite unreliable and 2) it leaves you with almost nothing (usually just a 3/1 auchenai and often the opponent has more from deathrattles). So while it is 'good', it isn't 'unfairly good' like some things other classes can do.
Holy nova i feel is quite weak if you don't have anything on the board. It's just an expensive consecration (healing face