My reasoning for the stunt, & the Claws power which happens to be from this forum, is that it would allow the character to use the Claws power to make defensive rolls with his weapon skill. I was thinking of it like the bubbles used in Changes during the Duel with Madame Ortega.
.
I happen to agree with you the only reason I have the Channeling is that it fit the concept, of a young orphaned apprentice but I can see dropping it to upgrade to Thaumaturgy, and saving a refresh.
I also understand that Evocation, is probably a better route to take than the Breath weapon, but don't want to get caught in the same old rut, of uber sorcerer.
I also put up a thread specifically about breath weapon, and Claws that includes most of the stuff on the other Breath Weapon threads but condensed and easier to read through. It is here, http://www.jimbutcheronline.com/bb/index.php/topic,25451.0.html