Phebius said:
Don't worry. If you play the game right, there's no way in hell a channeler will ever reach anywhere near 12th level
Although I know you're joking, it's kind of my point

If they can't get near level 12, what's the point? Midnight is supposed to be a dark, grim, and hard campaign.....not just a campaign where either:
a) Everyone dies. No characters can ever manage to crawl past lvl 5. TPK by DM just before they reach lvl 6. Why? It's Midnight, man! You're not supposed to live!
b) Everyone has a chance of reaching level 12....unless they're a channeler, in which case "you may as well hand over your character sheet now and go ahead with rolling up a rogue".
There are plenty of elements to worry about, like the clerics of the shadow etc., to give channelers reason to be careful with spellcasting.
But there are plenty of things a channeler should be useful for besides just lobbing fireballs. Charming opponents, hiding the party with illusions, casting an illusion of a road right in front of a cliff to lure an orc patrol to their doom, polymorphing into an orc to steal floorplans of a temple of the shadow, healing other party members, casting knock to get through a door, scrying, etc. etc. etc.
Part of this problem is that the 3.5 rules point arcane casters even more into being walking artillery pieces than they were in 3.0 by reducing the duration or utility etc. of many spells. And channelers in Midnight just aren't suited to that role.
Banshee