Hearthpwn

there are too many cases when Bring It On! can just make your things worse, you don't play it twice against empty-hand-aggro, you almost never play it against midrange decks cus your hand might just not deal with your opponents board by the next turn, you also don't wish to shuffle it most of the times so that card may just be dead in your hand, having a single copy of it in the deck seems quite reasonable

Why Public Defender?  isn't Doomsayer better in almost every other situation?

you rly don't want to shuffle neither Doomsayer or Public Defender with Dead Man's Hand, the only thing is the deck has enough board control & you can go full control almost infinitely w/ Dead Man's Hand value and the Public Defender just saves your face one turn ahead

is Scourgelord Garrosh necessary? 

It doesn't seem that OP in this deck, but it gives so much value sometimes. Not really sure about the replacement, the only guess is Elise the Trailblazer since you can shuffle the pack

Judging by my experience against it, I'd say yes. The hero power allows for endless clear with Sleep With The Fishes.