i made a ruling that you can cast Hex just like any other readied spell. You're concentrating on it anyway, so there's no real need to cast it on a critter to then kill. The real breaking from RAW is that I allow the casting onto a creature to still be a BA, instead of a reaction like readying a spell normally would be, and when initially readying the spell, I don't require a trigger - or at best, the trigger is generic like "I wait to cast the spell on the next creature I want to kill."
The point of casting it on a critter and then transferring the curse is that you DON'T have to obviously cast a spell in a situation where it would be noticed.
It's Eberron, not ebberon.
It's not high magic, it's wide magic.
And it's definitely not steampunk. The only time steam gets involved is when the fire and water elementals break loose.