On dwarf culture and grudges...to my limited knowledge Imperial Dwarves hold personal grudges. They still have the same psychology, a similar culture(noting that they're likely to form expatriate quarters or the like rather than dispersing evenly).
The big difference should be political separation. They don't (necessarily) consider themselves part of the Karaz Ankor, thus they do not inherit the obligations of the greater polity. With their lifestyle, they would have little need to maintain a formal book of grudges, personal feuds are such that generally speaking the human or halfling involved would be deceased and their lineage untraceable within a single dwarf's lifetime, so you either settle it right there, or it settles itself in a half century anyway.
But even so theres going to be some Back To Fundamentals type and those are the type that became Clan Huzkul.