[Jack Simth]

Try picking up a summoning spell or two, some battlefield control spells, perhaps some more buffs; sure, you can't do the mega-damage against that high SR critter, but it's rather awkward for the demon when he suddenly finds there's something threatening him... just opposite from where the Rogue is standing. It doesn't really matter if it's a fluff creature (at this level, something from Summon Monster III or IV is mostly fluff) as it still threatens, and grants the Rogue flanking. Sure, it's Full-round; but when up against things you can't affect directly....
Such spells as Heroism or Greater Heroism are also very useful - bonuses to Attack Rolls, saves, and skill checks? Very useful against those high-AC targets, or all that save vs. X stuff out there. The Greater version even grants temporary HP and immunity to fear....
Battlefield control ... well, this is an interesting one, mostly only useful when up against multiple or highly mobile opponents; wouldn't it be great to be able to pin down that archer who shoots three arrows and moves in the same round so Derrel can get a full attack in? Or maybe just a nice solid Wall of Iron ... or better yet, an unbreakable Wall of Force... between you and the thing that's trying to kill you....