Mulligan for the cheap stuff. Your main targets should be Dwarven Sharpshooter and Secretkeeper, both of which are amazing 1-drops in this deck. Phase Stalker is a good keep although ideally you'd only play it when you can guarantee a proc on the effect.

If you're not facing too many Dragon-decks, you may want to consider swapping Dragonmaw Poacher for something else, although a 4/4 for 4 Mana isn't the worst deal in the history of Hearthstone.