iceifur
Explorer
I stand behind my earlier comment -- the warlock starts ahead of the power curve, but soon falls behind. If you want to address some of the perceived power-wonkiness of the class, though, here are a few issues and some proposed fixes:
Thoughts?
Baleful Utterance may be (i.e. probably is) too good. Unlimited shatter is hardly kosher, regardless of when the ability would be obtained. Tagging the ability with some bonus effects was just ... wrong. Drop the invocation from the list, and it'll only be missed by those with an addiction to powergaming
. No harm, no foul.

The gimped range on the flee the scene invocation stops it from being too useful, and the image it leaves behind is a flavorful addition. If you tack on the same restriction that creatures with other at-will teleport abilities have (self plus 50 lbs of objects only), you have the perfect medium.
Any of the invocations that summon or create something temporary (swarms, walls, etc.) aren't completely boned by stipulating that the warlock can only have one instance of that invocation's effects in existence at one time. The utility remains without the warlock creating an open-air city of fire (wall of perilous flame, I'm looking at you).
Thoughts?