(And poor Halsin deserved better than to bear such a load of questionable content too.)
I see what you did there.

I think the only way you run into serious problems with him is, when you also play as a highly ambitious sorcerer or wizard and are dismissive about him and his expertise - but in that case the player character is just as bad. ^^
Or you can both be ambitious wizards, supportive of each others' plans and wreak havoc together. Fun times.
Still so bitter that a late addition character has better treatment, unique dialogue and cutscenes, and support from the companions than Gale does. Granted, her story is still not finished but everyone�s so nice to her right off the bat. Imagine if Karlach had the same dialogue options that Gale had� can you imagine the outrage?
(...) yes she gets a lot of special treatment - but fortunately, one can exchange her for a rather fine garment. That's how one gets accustomed to a mercenary's life.
If only we didn't need a damn mind flayer at that specific moment. This is the only reason for me to recruit her. I don't want to have to sacrifice my chara, Gale or Orpheus. Basicly, I'm forced to have her in my pt to have my desired ending.
When playing as Gale, you can learn that
the soul can be restored by divine intervention after the mind flayer transformation. This puts the entire plot on a different light, especially that ending scene, with all the people in the city transforming. Your generic wizard Tav will not be able to learn this.
It sucks that such important information is locked behind an origin. The whole game you're struggling and want to avoid the transformation, only to learn that the biggest reason you'd never want to become a mind flayer is actually not an issue.