Oh, for sure!
They are all very keen to learn more so if one of them decides to play a dwarf I will explain the importance of honour, oaths and grudges.
Sounds good. Dwarf honor is prickly and they should be ready to bleed, or at least pay some fines after trial, to keep it up.
This was one of the things I hoped the v1 supplement "Dwarfs: Stone and Steel" would address in detail. But the section on grudges is pretty vague and very, very short.
Some ideas for family or personal grudges: a stolen heirloom, a deceitful tactic in battle leading to a humiliating defeat that should have been a victory, a suitor whose romantic dalliance with a relative went awry, a very public insult whose response was inadequate, a loss in a very close competition for a prestigious job, etc etc etc
Those are good but in my opinion, or at least from the experience of gaming with my own group, Dwarfs can be pretty petty when it comes to grudges and can enter grudges for almost anything.
Some examples from my own games are; grudge for forced to pay extra for substandard beer, ambush by a bunch of bandits, GM cheating on behalf of some goblins in an encounter (for this one we claimed recompensation by killing a pet NPC of that GM), one PC hinting that the Dwarf PC was overweight and so on.
And do the dwarfs have a court of law where all of these grudges can be aired and settled nonviolently?
It would make things far to civil and effectively reduce the RP elements of having said grudges nursed and played out if there was a court of law for such things when you consider the Dwarfs traditional deferential attitude to authority.