I'd disagree with you on the whole "inevitable death" thing. Their death is no more inevitable than that of the Empire. I'll grant you decline, but you aren't seeing the other side of it. Its that same absolute sense of right and wrong that lets them withstand stuff like being cut of from the rest of the civilized world for three thousand years, and still be dwarves, still be normal for dwarves. Its part of the same package that lets them resist Chaos and magic. There's good and bad in it. Just like Humans and Elves. They have advantages and disadvantages.
Humans and elves can change, they can let go and they can even forgive. All these things are necessary to change the ultimately losing paradigm of the whole setting, the dwarfs advantages enumerated above only allow them to endure, to draw out their end.