This is a raid spec, not a solo/5-man spec.
You end up with most raid buffs increasing your spell damage.
The more stat buffs you have, the better the build is.
Almost every raid buff increases your spell power.
Str/Agi raises attack power, you get a percentage of your Int and AP as spell damage.

In a 5x shaman group, you won't have AI, MotW, Kings, Battle Shout, Might etc.
It's probably not the best build for non-raids, because of the lack of buffs.
Try it out, if you want.