Sam, honestly. stop the non-gathering professions. keep mining/herb/skin and enchanting (to DE stuff)
Instances will provide you much better green and blue items.

Regarding the cast sequence.
Stoneclaw is on a cooldown, you cant spam it.
Pull 1 group with your paladin, and have all your shamies drop stoneclaw, THEN fire nova (4 of each) then you need all shamies to do a Lightning bolt on whatever mob your paly is hitting.
Once the cooldowns for Stoneclaw and nova are up, repeat.

using oly nova is going to take too long because of the cooldown, so mana efficiency means nothign since the fights take longer.
you probably need 3 macros for the shamies. something like:
macro 1. just smash it all the time
/assist <paladin name>
/castsequence [reset=15] Stoneclaw Totem, Fire Nova Totem, Lightning bolt, Lightning bolt, Lightning bolt, Lightning bolt, Lightning bolt, Lightning bolt

macro 2. when the paly needs a heal
/cast [target=<paladin name>] Lesser Healing Wave

macro 3. when the shamies need a heal
/cast [target=player] Lesser Healing Wave

On the paly, bind macro1 to your threat abilities, macro2 to your ow shit button, and macro 3 to your taunt.