Heroics is a controversial one - I just don't like the idea of wizards getting fighter feats with a spell. Not least because it lets them access tome of battle maneuvers, and you can combine it with imbue summoning to give your summons context-specific feats such as mage slayer.
Not just the wizard, it can also be a buff for allies. It's very powerful, but I don't think it's necessarily broken. In my games I did make it Bard 2, because i can't understand why Bards shouldn't have a spell like this. They can Inspire Heroics, but they can't cast it? As for Mage Slayer...it does have requirements. Maybe the spell doesn't say it clearly enough, but I rule the recipient needs to meet the feat's pre-requisites.
In one game, a player made a focus caster transmuter, who could then, via his class feature, give two people Heroics in a single casting. That was kind of crazy.
Owl's insight - insight wis bonus of 1/2 caster lv, and divine casters already have no lack of ways to augment their caster lv...
What's the spell level and duration of this again? I'm pretty sure there's a reason my current cleric doesn't bother to prepare this... And I don't know that many ways to augment CL. The biggest one that comes to mind is Divine Spell Power, which needs a feat and a very good turn undead mod to get the maximum +4.
Anyspell now available to everyone, even those who did not sleep with Mystra?
That doesn't make it broken.
Hunter's mercy...fairly self explanatory.
Again, kinda think Rangers and the other "weak" classes should have awesome spells like this. I don't think it's too much, but it is very powerful.
Unimportant side-story: My lightning-focused Evoker was in a duel once with a archer ranger. I had taken a weak prestige class that fit him thematically, Stormcaster (lost CL = weak

). He tried to use hunter's mercy on me, and I spellcrafted it and used my 1/day immediate action wind wall to negate it. Good times!
Ray of stupidity - more irritating than anything else, because now, the DM can't throw foes with int scores of 3 or lower at the party.
Yeah, this one should probably just be banned. It can't really be nerfed as it already does so little ability damage. It's basically just a "win button" against low int creatures, and not worth using (without being empowered, twinned, repeat cast, etc...) any other time.
In my current game, a PC has Dragonfire Adept and took a breath weapon that inflicts -6 str penalty to the victims. There is a save, but it merely halves the duration, not the penalty. Which means I can't use anything with 6 str or lower unless it's immune to the effect. I really miss swarms.
To be fair, SC did try to balance out a number of clearly problematic spells (such as fleshshiver and quill blast). But true to 3e, they ended up creating more issues than they resolved.
I disagree. The book has a LOT of spells in it, and thus far, only about a dozen have been identified by at least two people in this thread as broken.
It is typically much easier to abuse wraithstrike than truestrike.
Wraithstrike is a swift-action spell and lasts for the whole round, meaning a gish could cast it and still make a full-attack. Alternatively, if the fighter could somehow access persistent wraithstrike (say via a ring of spell storing, or if your party has an incantatrix...).
Then the DM points out how dragons too benefit a great deal from said spell, and the players agree to swear off its use forever.
Agreed. Wraithstrike is broken because it's so low level, a swift action, AND benefits all attacks that round, while True Strike and every other melee touch ability I know of is only for one attack.
Now, with all the debate over whether it's ever balanced to get a melee attack as a touch attack, I would like to point out two things.
1) Unless the target creature has 20+ natural armor / armor / etc... True Strike is giving a better bonus than any melee touch ability.
2) This SAME book also has a level 2 sorc/wiz spell called Scintillating Scales, which for min/level causes the caster's natural AC to count towards his touch AC! And you know, dragons have a tendency to both have huge natural armor and sorcerer spellcasting... Just saying.