I have used something like this in the past with 3 macros, I am at work so the syntax may not be exact but the idea is the same. It works good for keeping all your macros in the wow client and keeping them shorter.

Macro 1 (this is the one i spam for dps)
/assist TANK NAME HERE
/use [combat] 13
/use [combat] 14
/use [combat] Elemental Mastery
/click ActionButton12
/swapactionbar 1 2

Macro 2 (this is on page 1 action button 12)
/castsequence Flame Shock,Lightning Bolt,Lightning Bolt,Lightning Bolt,Lightning Bolt,Lightning Bolt,Lightning Bolt,Lightning Bolt,Earth Shock,Lightning Bolt,Lightning Bolt,Lightning Bolt

Macro 3 (this is on page 2 action button 12
/castsequence Call of the Elements,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Searing Totem,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst,Lava Burst