The notes for Fortemps and Haillenarte seem fine, other than misspelling Edmont's name - and not listing "Lady Ninne of House Fortemps" at Dragonhead, who gets one brief mention in MSQ and another in a levequest, but doesn't seem to be a close relative of the others.
But the others...

Originally Posted by
Sounsyyv
House Durendaire, the Bell
Founder: unknown
Important People:
-(unknown Count)
-Ser Forlemont de Durendaire (brother of Count de Durendaire, heads the Observatorium)
-Carvallain de Gorgagne (Captain of the Kraken's Arms in Limsa, supposed lost heir of Durendaire)
-Lord Drillemont de Durendaire (second son, controls the Whitebrim Front and now Stone Vigil)
-Lord Jannequinard de Durendaire (third son of the Count, teaches Sharlayan Astromancy)
-Ser Yuhelmeric de Brillelame (former Lord Commander of Durendaire's Knights)
-Ser Redwald (commands Falcon's Nest)
Even before I had the lorebook (never mind the recent
corrections), some of this information sounded off. They've assumed Drillemont is the second son despite nothing directly implying it - it's not a bad
guess from the information they had (particularly both other Coerthan outposts being manned by sons of the House in charge), but it shouldn't have been listed as an absolute.
From the lorebook we now know that Drillemont
de Lasserrant isn't even part of the family, and is nearly as old as the count.
I don't think Forlemo
rt was ever referred to as "Ser", and was only ever noted as Jannequinard's uncle, not definitely the count's brother - he could have been married to the count's sister, or from Janne's mother's side of the family.
From Fernehalwes' corrections, Forlemort isn't even strictly Janne's uncle (=sibling of a parent) but in the loose sense that you might address any older non-grandparent relative as an uncle rather than the exact relationship.
The lorebook confirms that Carvallain is the count's son - and recently corrected to be his
only son. Apparently owing to a mistranslation of Jannequinard being "third in line" as being the count's third son, but he is actually the count's nephew. Another (unseen, un-named) nephew is second-but-essentially-first in line.
* "Carvallain" may not be the name of the count's son, technically - we know his surname is an alias (Ser Gorgagne was the knight in charge of looking after the boy at the point when he vanished) and it's likely that his forename is as well.
Bonus family listing from Fernehalwes: "Lord Portelaine (stationed at the Observatory) is a (low ranking) member of House Durendaire and distant relative to Jannequinard (most likely through marriage)."
From the lorebook, we additionally know the founder is Guenriol de Durendaire (the lorebook does say "Geunriol" but I think it's a typo, since we've seen the name spelt the other way in-game) and the current count is named Charlemend.

Originally Posted by
Sounsyyv
House Dzemael, the Rook
Founder: Sylvetrel de Dzemael
Important People:
-(unknown current Count)
-Lord Tarresson de Dzemael (former Count)
-Baron Thieveneux de Dzemael (master of House Dzemael and wealthy patron of the Temple Knights)
-Ser Grinnaux de Dzemael (trueborn Duskwight son of Dzemael, one of the Heaven's Ward)
-Archombadin de Dzemael (trueborn Wildwood son of Dzemael)
-Lord Tedalgrinche (Lord Commander of Dzemael knights, possibly son of Dzemael?)
-Jandelaine & Guillefresne (not trueborn)
"Baron Thieveneux, master of House Dzemael"? I had to re-read the levequest description to even work out where they got that out of it, but I think it's ambiguous.
Landing the Big One
It has been said the best deals are struck during a session of fishing, and it just so happens yours truly was invited by
Baron Thieveneux of House Dzemael, a staunch and wealthy patron of the temple knights to partake in such a leisure. Outside of the capital? Halone forbid! No, no, I have been invited to the manor's expansive ponds, stocked with the best and built by Dzemael hands. There is much profit to be had for the coffers from a leisure such as this, so I find myself in need of a fine cedar fishing rod...though not too fine, mind you. I would yield the fattest carp to
the master of the House of Rook as I try to catch even bigger fish.
- master of the House?
...bother it, I'm going to have that song from Les Mis in my head all night again.
- the [fishing] master?
- Is the count coming on the fishing trip as well? And the leve requester is trying to catch "bigger fish" than the Baron who's already a patron?
In any case, a
baron ranks lower than a count.
(I do have to wonder where in Ishgard they are managing to fit these fishing ponds, though...!)
Re. the discussion on page 2:
Tarresson is a Wildwood.
Ser Grinnaux - confirmed by the lorebook to be the count's nephew. And as I said earlier, it's more likely he's "Ishgardian with a Duskwight appearance" than actually a Duskwight.
There's also the confusing phrasing "a son of House Dzemael" which seems to cover other family members and not just the direct sons of the count.
Tedalgrinche - I don't recall the title "lord commander" coming up at all. (I'm pretty sure that's strictly Aymeric's title.) It sounded unfamiliar when I first read this page a while ago, and still again after replaying the MCH quests recently.
Without reading through every quest again now, just some key ones...
- in his first appearance before being addressed by name, he's labeled as "Pretentious Noble", not a knight.
- he does seem to be in charge of Dzemael's knights, at least during the battle in western Coerthas.
- he and Stephanivien seem to have known each other a long time.
I would guess that he is part of the Dzemael family, but there's nothing clearly stated either way.
"Jandelaine & Guillefresne (not trueborn)" - either a strange misreading or a misunderstanding of the term "trueborn", which seems to simply be the opposite of "illegitimate". I think they might be using it to mean what the game actually use the term "son of House X" for.
Guillefresne's quoted dialogue just says that they're distant relatives.
Ah, but where are my manners? I am Guillefresne, of House... well, you are not like to know of us, but perhaps you do know of House Dzemael, with whom we share common ancestry.
And the list of minor houses...

Originally Posted by
Sounsyyv
-Brillelame (Elezen House, Yuhelmeric de Brillelame)
-Rougecarpe (Elezen House, Ansaulme de Rougecarpe)
-Gorgagne (Elezen House, Carvallain de Gorgagne)
-Valentione (Elezen House, Countess Arabelle de Valentione)
-Bale (Midlander House, Azure Dragoon Alberic Bale)
-Jervaint (Elezen House formed backbone of Temple Knights, Baroness Laurisse de Jervaint)
-Caulignont (Elezen House, Rielle & Ystride de Caulignont)
-Bonfaurt (Wildwood Elezen, serves Dzemael)
-Maintigny (Wildwood Elezen, Crammevoix de Maintigny)
-Courcillan
-Centurio??
A band of fearless monster hunters brought together by Ser Leaudaste, the Ishgardian noble who won fame and fortune as the original monster hunter.
There's mention of a Duskwight House Nevelle, however, it traces its roots from Vylbrand, and there's no evidence that this House is Ishgardian.
I was able to find a lot more nobles in the various Disciple of Hand quests, but most don't have the surname/House names attached to them. Glenda and Gerhardt are both Hyuran Ishgardian nobles, but there's no mention of their House.
I don't think Bale should be on that list. Alberic is a knight, not a noble - as far as I'm aware. And I know I saw a quote recently that knighthoods are earned, not inherited - it might have been in one of the levequest descriptions. (EDIT: Most tellingly, he's not Alberic
de Bale so it seems unlikely that he's a noble.)
Not sure where Nevelle is noted as a Duskwight house.
Glenda (the mother from the WVR quest) seems to be a noble, though perhaps could be wealthy middle-class - I'd have to re-read the quest script.
I think Gerhardt (LTW) is just a wealthy merchant.
And there are a few more houses that could go on the list, but that's for another time.