It's a pretty well-built deck, but I'm not sure you have too good of a backup plan if you don't draw Dreadhorde Arcanist. I'd throw in Grisly Salvage to dump good spells into the graveyard as you look for him.
@Rooker : the
backup plan / alternative strategy is
Young Pyromancer. Both can be the focus of any game. Together they're even better.
Arlinn Kord in particular is great in this deck : she can give +2/+2 to a single threat or +1/+1 to all tokens/creatures.