The Duergar make some cracks about you usually being their target, or how you should be digging with the others, but I don't remember much else.
As for the Gnomes not trusting me, I didn't talk to them until after killing the Duergar in front of them, and then Nere (who I also decapitated in front of them) so maybe a little benefit of the doubt is in order for one of your kin...guys?
I'd also like to mention, my second go at Nere, I disarmed him, picked up his dropped rapier; which was stealing! And had to reload when the Gnome turned aggressive after saying something akin to; "That's enough of that from you!" So the
Gnome IFF is still in effect.