Goblin Wardriver is a good addition, for sideboard, consider Raid Bombardment as it can enhance damage or Impact Tremors in case you run up against hard control or Death and Taxes, as this can keep your damage valid. Also consider Ghost Quarter for the sideboard. It stops 12Post, Scapeshift and othet nonbasic heavy land decks pretty quickly.

Nice deck. Plus one from me. Also check out my Screamin Jay Goblins deck.

Hey there addhistory, just kinda saw the deck and thought i'd help out a little. For sideboard, I would definitely recommend the new Rending Volley. The premium sideboard card for red used to be Combust, but I believe Rending Volley to be a tad bit better.

Since you're using cards like Krenko, Mob Boss, Mogg War Marshal, Foundry Street Denizen, Warren Instigator, and Krenko's Command, another new card you might conider using is Impact Tremors. To this extent, if you're willing to spend a little more money, Goblin Rabblemaster could also be a nice inclusion to this deck as well.