Let me start by saying that Gloom is the most brilliant game I've encountered in a while. Lots of fun and still room for tactics and good gameplay.
I was very eager to get the expansions too, and for Unhappy Homes I really like the idea that each family gets a special ability, as stated in the Unhappy Homes Promo found on the website: atlas-games.com/pdf_storage/GloomHouses.pdf
However, this idea isn't really carried over in full for Unhappy Homes, and so you have to make some house rules regarding this aspect. First of all, since there are a new home in each expansion, we're two special abilities short in a full 6-player game. I have some ideas for this, and I'm curious to get feedback on the game balance.
Let's first recap the 4 initial abilites as stated in the GTM article:
Dark’s Den of Deformity:
As your first play, you may discard 3 cards from your hand to remove the top Modifier from a living Character you control.
Castle Slogar:
Whenever a Modifier is played on a Character you control, you may discard 1 card from your hand.
Hemlock Hall:
After you draw from the deck, draw 1 additional card and then discard 1 card from your hand.
Blackwater Watch:
Whenever you play an Untimely Death, you may immediately play 1 Modifier as a free play.
This all very cool. Now for the new families, I'd propose the following abilities:
Le Canard Noir:
Whenever you discard a card instead of playing one (as one of your two plays), you may draw 1 card and immediately play that card as a free play.
Rationale: The Canard Noirs are haunted by bad luck, yet they always seem to get a second chance.
The Broken Arms:
Whenever an opponent plays an untimely death, you may randomly select and discard one card from that players hand (this goes before any free play, like the Blackwater Watch ability).
Rationale: Unauthorized killings don't go well with this gang of mobsters, and the punishment will be swift.
Story-wise I think the abilities fit, and game-balance wise, I assume they're all good, but I'd like some feedback on this. Are any of the abilities broken? And if yes, how could they be replaced with something in the same spirit? Comments much appreciated! 
The second thing regarding these house rules are: Should these abilities be in effect permanently, or should they be overruled by Mysteries, just as if they were printed on the House card itself? I haven't tried to play with these rules yet, so I'm not sure what would work best... Again, comments very welcome.
EDITS: We tried playing with these rules today, and it worked very well I think. You should try it!
Regards, Artur