Yeah there are a LOT of things wrong with LB+LB+CL, the first of which is that /castsequence is not a good thing to use - it will cost you dps because there is a delay between items. Not only that but theres no need to use a castsequence on a shaman. You're better off just using a castrandom and throwing all your DPS spells into it such as:

/castrandom Lightning Bolt,Chain Lightning,Lava Burst

You would then open up a fight by using flameshock x3 and then you could start spamming the above macro. I can tell you thats basically all I do and my elemental shamans hit around 1600 dps, and I never refresh flameshock, if I did it would be higher.