There is a dragon breath power I hear mentioned in some dragon magazine. Supposedly it's nice to stack metabreath feats on.
Actually, that's Gemstone Breath, from Dragon Magic, and it doesn't come online until later. Unless it's a power I'm not familiar with.
Non-flying foes are great to use with the Grease power. It lasts 1 round/lvl and remains powerful into epic levels.
Are you a StP erudite? I'm going to say 'no' since you didn't specify.
Beyond that, Energy Stun is the only option you have for an actual AoE direct-damage power at this level, though some cleverness and wit can take you far.
Craft (Alchemy) can grab you acid and alchemist's fire. Psionic Minor Creation (to funnel into vials you bought beforehand) can net you splash weapon poisons and any plant-based acids and such (for bonus points, create pine pitch, throw pine pitch, light fire to pine pitch, and voila -- flaming pine pitch splash grenades!). Control Air isn't specifically damaging (and it's a kineticist discipline power besides), but it's a level 2 AoE, and you can make tornadoes and things for damage later on. There's also Demoralize, of course (but that got mentioned right before me).
I'd say your best bet overall is alchemical items and clever use of Psionic Minor Creation.