Fair enough, I really just posted this here because I think this a good thread where members can discuss this sort of thing. Anyway I'll try to explain my methodology for obtaining the equation I used to compare hit/crit/spellpower more clearly.
We know that the damage you do through hits is from both your base damage of the spell and your spell damage multiplied by the spell damage coefficient. Base damage for frostbolt = 486, and the spell damage coefficient = 0.814 (Although after doing some testing I really don't think this is true I believe it's closer to 0.914 but that's beside the point).
Anyway your damage from hits will then be:
486 + 0.814*Sp = Hit Damage
Note: Sp = your spellpower.
Now if we wanted to consider crits, let's assume our crit rate is 25%. If we wanted to compute our damage per 100 attacks we'd do:
25*2*Hit Damage + 75*Hit Damage = Total Damage
The 2 multiplied by the 25 is from the crit multiplier. So the equation just shows that 25 of our attacks will be multiplied by 2 and 75 of our attacks will simply be our hit damage, adding them together will give our total damage.
Now suppose we wanted to consider resists from lack of hit. Let's assume we have 90% chance to hit (+7 hit from gear).
In this case we'd break Total Damage into two groups, hits and misses.
0.90*Total Damage + 0.10 *Total Damage * 0 = Hit Adjusted Damage
So basically you can think of the 10% of spell that are resisted as losses that are multiplied by 0. Essentially since we only hit on 90% of the spells our damage goes down by 10% (ie multiplying our damage by 0.90).
And that's basically it. The equation I showed in my previous posts is this equation it's just more generalized. Anyway I hope this makes sense.