Ya sounds to me the lightning bolt scales just horrible.
I don't even know if a spell damage talent would help that much, shamans are going to have good spell damage from just buffs as it is 275ish from flame tongue and another 280 from Totem of Wrath if spec correctly.
The problem is Lightning Bolt gets no bang for your buck, blizzard really want shaman to use flame shock in our rotation without ******** us up I am starting to think they need to completely change Storm, Earth, and Fire. Maybe make it so that flame shock has charges like storm strike that only buff the caster (like the new storm strike does). With each point in SEF flame shock gets an additional charge that can be applied to a enemy when affected by Flame Shock. Whenever an enemy takes nature or fire damage from the caster a charge would be consumed making the target take an additional 20% more damage. I would also leave on the increase range with Earth Shock for PvP sake but I might even say increase it to 15 yards but maybe now I am just being greedy.
Anyhow with a change like this then shaman would be in much better shape, a rotation of Flame Shock>Lightning BoltX3>Lava Burst would be very useful shaman would be up to par on damage, and gameplay wouldn't be as boring. Hopefully something happens soon because if Lava Burst and Flame Shock where not useful enough for shaman to add to there rotation Blizzard is going about things the wrong way by nerfing lightning bolt, make the rotation usfull if this is what you want blizzard don't make elemental shaman useless.