This is why I provided ready made and proven macros for the task. Took me DAYS to figure out, test, debug, rewrite, retest, debug again ... wash, rinse, repeat ... to come up with the macros you see in this post. Once you get used to using them, you'll start to wonder how you managed to get so far without the "automation" that the macros offer you.
Spellpower heavy Hunters are a decidedly odd ducky ... mainly because of how few Hunter spells are actually tied to spellpower. There are SOME ... just not all that many.
One of the more obvious possibilities is to stack up healing spellpower and turn your Pet into an absolute BEAST of a Tank that you can heal up relatively easily. This variant typically derives more benefit from Beastmastery than from Survival investments (for what should be obvious reasons).
Aside from various Stings and Arcane Shot, the only other major source of spell damage on a Hunter (that isn't dependent on equipped gear) is going to be your Fire Traps. However, I am unsure if Trap damage is modified by spellpower (haven't tested). Raptor Strike, Mongoose Bite and Counterattack (your melee bread 'n' butter attack spells) are all Physical damage typed, so they use Attack Power rather than Spellpower to increase their damage output.
That said, if you've got a build that is loaded with Chance on Hit for spell damage effects, you could theoretically leverage spellpower boosts ... however since most such random procs are effectively Instant cast one has to wonder what kind of spellpower coefficients you'd be looking at. Then you have the flipside of trying to calculate the "cost" of going that route relative to the alternative(s), so as to weigh the relative merits of either option.
So while it CAN be done, the real question then becomes the relative value/advantage of pursuing that path. I'll let others expound on the possibilities to be found there.