In other news I am mostly through the Underdark and still inexplicably not dead, though I did manage to lose some items to explosions/cliffs - I wasn't trying to shove that guy off a cliff when Karlach threw a spear at him, but I guess the elevation and angle did it anyway!
More concerned about Act 2 because I screwed it up royally in my first run so don't really know the "right" way to do it, or the "right" order of places to go. Also I keep telling myself I will take the safe and pragmatic options in dialogue and then the moment the chips are down I'm talking smack to people I really shouldn't.
Also as I predicted I did indeed walk into the exploding mushrooms (sigh). I managed to save the guy first but I didn't think carefully and so sent my STR 8 character to throw water at the torch instead of say, shooting it with an ice spell or ice arrow or using a proof thrower like Karlach. RIP special mushroom.