you have 3 Searing Blaze in the main and 2 in side...

Why splash black for only one card in the main, Bump in the Night, and one card in the side Rakdos Charm?

In my opinion add a play set of Lightning Strike for instant speed and more constintency.

By the way, good deck! +1

@arfio

I forgot to edit the sideboard, so thanks for reminding me.

Regarding, Lightning Strike, it is a no for me. I would rather have Incinerate which is far better. Bump in the Night is a black Lava Spike and costs only 1 to cast and I can always cast it consistently.

Burn spells that deals 3 damage for 2 mana (with a few exceptions) is usually a no go for Modern Burn.

Check-out this burn deck primer here: http://www.mtgsalvation.com/forums/the-game/modern/tier-1-modern/219892-burn

Cut two Lightning Helix for two Grim Lavamancer

I build a similar burn deck. and it feels awesome to play :)