I think you're running entirely too many lands for an aggressive deck with a low curve. I would cut it down to 24 or even 23. I don't like the
Vanguard's Shield in this deck. The point of this deck is to unleash, so your creatures wont really be blocking anyway. I also don't like
Curse of the Pierced Heart, which has synergy but the one life won't make very much difference in the long run. Same goes for
Shrieking Affliction, which feels more like a combo piece than a value card for you (unless you run hand attack, which is a cool idea, but not this deck's style.) Consider cutting
lobber crew and
Wight of Precinct Six. I like suggestion of Spike Jesters, and there are good one or two drop pingers out there, like
Goblin Fireslinger, and
Goblin Arsonist.
You want more lightning strikes,
stab wound,
pillar of flame,
Vampire Nighthawk,
ash zealot, and
bloodfray giant. Consider picking up
Rakdos, Lord of Riots or two. They are only about a buck or two.