A change to ToW needs to be made. Currently, we're mostly brought in for that alone. I haven't run with a Demo Lock in awhile so Demonic Pact is very rare, but if that's brought in what do we do? Lay Searing Totem, sure that helps our DPS but it certainly wouldn't make us competitive.
Proposed changes:
1) Make ToW scale ala Demonic Pact. Either make it a flat bonus that scales with Spell Power, or whenever we crit with Lava Burst we get an increase in Spell Power on top of ToW based on 5% of the Shaman's Spell Power. The latter making the most sense to keep it consistent with how Demonic Pact works.
Math:
My Shaman has 2880 Spell Power + 280 from ToW, with a lava burst crit, the raid gets a buff called "Wrath of the Elements"
2880+280(ToW) + 273(3/3 Elemental Weapons Flametongue Weapon) = 3433
3433 * 0.05 = 172 additional spell power for the raid
This value of course does not reflect buffs from: food, flasks and trinkets.
2) Instead of a flat increase in spell power from Flametongue weapon, make it percent based. Currently, (talented - Elemental Weapons) you get 274 spell power from flametongue.
Proposed change:
Base: Flametongue grants 9% increase in spell power
Talent increases that percentage increase by 1%, 2%, and 3%. Therefore, 10%, 11% and 12% increase.
My Shaman currently has 2880 SP unbuffed, with flametongue: 3153
With propose change:
Spell power with untalented Flametongue: 3139 - roughly on par what it is now.
1/3 Elemental weapons: 10% increase, 3168
2/3 Elemental Weapons: 11% increase, 3196
3/3 Elemental Weapons: 12% increase, 3225
That would give me a 72 spell power increase. This would alleviate any future issues with Shaman scaling.
Now let's factor in ToW.
Current Flametongue + ToW + my current Spell Power: 273 + 280 + 2880 = 3433
Assuming unglyphed ToW
ToW + currnet SP = 3160
New Spell power values:
ToW + Flametongue(untalented) = 3444
ToW + Flametongue (1/3) = 3476
Tow + Flametongue (2/3) = 3507
ToW + Flametongue (3/3) = 3539
Total Spell Power gain: 3539 - 3433 = 106