Wow -- I go into a committee meeting for an afternoon and this place goes nuts in my absence!
To answer the various questions:
Nuru and
Imladris: I have imagined these members of the nobiilty as being extremely powerful members of the royal court: that is, they have large amounts of property and control a vast amount of wealth. This is a feudal society, so they will have armed soldiers and cavalry of their own, but these troops will, of of course, be part of the king's army and under royal control. Think of your characters as the "colonel's" of your soldiers with the King and his general (Kransha's character) as the, well, generals.
Given that they have wealth, armed men and land, they have political power. Their opinion has real weight and they know this. Depending on where everyone lives, the two analogies that work best I think are that these nobles are powerful Senators to the King's President, or front bench cabinet ministers to the King's Prime Minister. A Middle-earth analogy would be that these nobles are like Prince Imrahil of Dol Amroth, or Erkenbrand of the Westfold.
As to their families, living arrangments, and day to day lives, I leave those entirely up to you.
Imladris: not a silly question at all! Again, I leave it to you guys to decide if they are related -- but if you want my opinion
I would think that it might add to the drama of the story if they were related, but not on very good terms. . .
Orofaniel: not too late at all. Put up the description at your convenience.