To start, your board is kinda terrible. The standard is:
4 Gemstone Mine - A must. Your going to need 8 colored mana sources post board to play your spells.
4 Emerald Charm - Leyline is your biggest threat (as you can't win with it in play), so all of your removal spells should be able to get rid of said enchantment. Emerald Charm is an instant and has other relevant abilities (untapping a Bazaar, making an attacking Angel lose its wings) that put it on top of other spells.
4 Chain of Vapor - For dealing with everything, from Needle to Jailer to Platinum Angel or Leyline
2 Wispmare - Gets around Thorn, makes Bridge Tokens
1 Random - Typically a DSC or Darkblast
You typically side out your Dread Return package (possibly keeping in a single Dread Return to resurrect a Grave-Troll/make tokens) and any of the following depending on matchups: Chalice, Leyline, Unmask, Petrified Field. Additionally, you'll likely side out a bunch of one-ofs, like Thug, Imp, Ichorid, etc.
Lastly, I'd drop a Stinkweed Imp for the 4th Thug. I find being able to hardcast a Thug is far more valuable than 1 extra dredged card.
Hmm, I think I like your board.
I know my board looks terrible. haha That's my biggest problem, as of now...
anyways, In an aggro infested meta (bunch full of Sui-Blacks, Platinum Oath aka "Steel Battallion", Hate decks, Goblins, Fish Bomberman and Staxx), wouldn't it be nice to run atleast 3 Contagion in SB?