I've invented a whole crew!
The fact that there are two Allomancers in a reasonably normal family suggests that they have a strong bloodline, as well. It lends a bit of irony, then, that they are so unconventional (as far as nobility is concerned, anyway) in their treatment of skaa.
I also like how rivalry with a powerful house (Cett) may develop because they are harboring a murderer. Gork didn't kill everyone, which means that, should he show his face again and be recognized, a world of hurt may come down on the whole household because of that act of mercy. I can also see some drama between Mars and Melenius over what to do with Gork should the secret get out.
This is actually the other way around. The Tersius allomantic strength is a reward from the Powers that Be for being such noble nobles.
Tersius and Cett were already rivals. Sort of a case of two alpha males in one territory. And most of the survivors are actually part of House Tersius now.
Is it just me, or is zinc popular with the pretty ladies? I was considering something similar, but noticed that Sayna is already covering that role. Kobe is set to be a Rioter, too. Is this part of some "Femme Fatale" trope or archetype, maybe?
Kobe is modeled on Sayna a bit.