Probably Gale. Due to the dark urge path. I don't hate him and he is nice and easy to please but it will set a darker tone to the adventure. Now if there is a second chance to recruit him, I will do so.
But yeah, with the dark urge nobody is safe.
But I will try my best to keep the others, though.
Personally, I find Lae'zel annoying but one companion less is already a hit. I can't afford losing more, esp. with the unpredictable stuff that can happen.
As for Halsin vs. Minthara, in EA I stuck with the tieflings. But I am going for a very chaotic run (though I won't go ultra-evil), so anything is possible.
I don't think the best approach to the urge is to give in literally every time. Even if you plan to embrace the dark urge and the evil playstyle it would be wise to still build and maintain a party of companions. I get the Dark Urge is probably an avatar of bhaal or some such but that doesn't mean I always have to behave as bhaal would. Corrupting evil so much more fun than just stabbing though I am sure there will be more than enough opportunities to stab things to satisfy the dark urge anyway.
