Do exploring the caves actually make a difference? I found a mammoth so there appears to be some random chance for something, but I dunno if it affects the plot.
I'll have to try the council alive later. I got unlucky with the ratmen shop this act and now I'm short on healing/rejuv potions. Krimm's wave is pretty rough. If you wanted to be nice, you could increase the potion supply they sell.

None of their equipment has been useful all expansion.
In an alternate universe: if you kill the council, your party heals between gnoll waves, but Daronas and the guard do not. Also, with a four man party and Daronas the warrior, I think it'd be more helpful to have the archer volunteer than the warrior guard. And that's even with a non-Ranger Shea.