Dwarven obsession with mining and kin could be further explored by making them a marginalized folk with a red kind of empathy for others like them that are marginalized. To the point that dwarven mining is focused on exhuming the bones of the dead - their dead, or the dead of those marginalized folk whose causes they have decided to champion. Given them an M.O. to the effect of, 'dwarves fashion chain-like armor from the bones of the marginalized because they believe it lends them righteous strength.' This could be turned into something lucrative in that you could have the dwarves looting the ruins of those they've gone to war against (the people they're warring against being those that the dwarves believe responsible for marginalization of whatever peoples the dwarves are championing).

Dwarven logic for the looting? 'We're removing the temptation of expansion - these riches - from the path of the survivors and any that may come across the battlefield.'

Did I just make Mardu Dwarves?

eH, i - apparently had capslock on, sorry. Ahem
I don't know how onboard I am with that, but it dovetails nicely with another idea I've heard; Dwarves aren't born- they're excavated. That would give them an emotional drive to excavate and expand. Dwarves probably can't be mined just anywhere.

This should be the plotline of a block

They had the Lorwynn block which had no humans, but that wasn't part of the plot.

Time spiral but they have to throw all the humans into a black hold to patch the super-rift.