Lords should have a Custom PrC that should function similar to the Ruby PrC class. Not necessarily a 'class', but should be rewarded through the effort that the player took to achieve the notable ranking within the Dominion.
The Perks would include-
Able to "Knight" players, after being recommended by DMs if they are seeking that particular lord. (Application Passed, an OKAY from the Dms.)
Custom feats for persuasion, bluff, and intimidate.
A scripted pay system representing the "Taxes" They gain from a fief or holding they control.
Etc...it's an idea.