Sometimes, there's someone who knows an answer but isn't willing to detail it for lack of time or good will. That's when a bounty could be useful, provided that someone cares about reputation.
My vision is that in your case, there's either no one on this site that has a really good answer to your question (rpg.se is quite small compared to, say, stackoverflow.se, and it's entirely possible no pathfinder player here has a clear idea of one of the widest, most DM-depending aspects -- namely, spells -- especially when applied to an unusual case) or those few who know are not interested in spending much time to answer, either because they don't care about reputation or because they already have lots of.
Since you also asked for what makes your answer hard to reply to, I'll detail my thoughts on the matter; they're by no way the one and only truth.
In D&D 3.PF, spells are really powerful things that could make or break a plot. Which ones are best for the same specific situation heavily depends on how your DM DMs. Which spells are good depends on which enemies your DM likes to make you face and the spells those NPCs use, but mostly getting a hold of every good spell that's ever been written for any class is a gargantuan task. I know, because I played a Chameleon for D&D 3.5 and just getting all the divine spells up to level 3 down took me lots of free time in the course of a whole year.
Still, I was not sure my choice of spells was the best one. I specialized in buffing, so knowing which spells would be better for, say, debuffing, would have required me to spend another whole bunch of time on the books, reading and comparing options. Until you find whatever the definitive list seems to be, and discover a 5th level spell from another class makes your whole debuffing irrelevant, because D&D and PF are written that way. (I had this while planning enemies for a D&D 3.0 campaign when the cleric began casting Iron Body. Days wasted planning unuseful strategies, oh-the-rage.)
I don't think there's any reputation bounty that could convince me to start a whole dissertation on such a complicate argument, while I'd be more than happy to spend entire afternoons telling you why each single spell is or is not a good idea to me (in D&D 3.x, not in PF, since I don't know its options well enough).