The circuit mage was concieved as being a warlock with less absolute power but greater potential versatility than the normal one. Though of course there are always spells that, when given at-will, might break a given game, so a DM would still have to look out whats happeneing.
The picture is from the game "The Void" (I believe in some parts its called "Tension"). I had recently watched the Let's Play of it and it jumped out at me.
Yeah, there are still some typos in there, but honestly I had all but forgotten I had made this class since I didn't get many replies and I was on a "have to play in an epic game" trip at the time, which led to it not being allowed in those since it gets very strong very fast once you hit epic.
I'll have to look at the blue mage, but the general idea was that the circuit mage can use scrolls or wands to zap himself if he needs to.
Yes you are most effective with another caster in the party, but that was actually a calculated effort. I wanted this to be somewhat of a fifth-wheel character class that however can be very useful if managed correctly. As such I made it to reward staying in the class with many of the best features only coming later.