You get them from BBI. They are augments that once you unlock them, you are able to apply them to both your character and your pawn. So far the only one that I've found to be of any use is Tenacity. It puts you at 1 health any time you're hit with an attack that would drop your health below that with a massive hit.
I know that Sorcs do well against Ur dragon, but have you played a Magick Archer? I don't know if a Sorcerer is "the best" at killing Ur, but they are certainly one of the best.
I also don't see how our Sorcerers "go completely different routes". They aren't that dissimilar (what are these "status spells" that I supposedly take that you don't?). The only thing I don't do is carry around more than a single "giant" spell, because aside from flavor, Maelstrom and Bolide are too similar in outcome.
I haven't played a Sorcerer in BBI yet, but Voidspell did absolutely nothing at all in vanilla for me other than to cure petrification. Did they change it? Because it was supposed to remove all kinds of status effects, especially those that affect stats (curses), but it never seemed to do anything at all other than take up a slot.
The whole Fire > Holy was not in regards to usefulness. It was just that you don't actually get Holy Affinity right away, and Fire is more useful starting out. Holy doesn't really do anything against Ogres and Cyclops either. Once you're near the end of the game, and especially post, it's either Ice or Holy. I don't really spam the charge attack though on most enemies. It takes way too long to charge just to kill one enemy at a time as opposed to simply casting a multi hitting spell that will kill more at once and that has a similar charge time. I can't remember the last time the Holy bolt actually hit more than one enemy at a time.
