I'd like to use the Influence and Subtlety mechanic from the beta for my upcoming DH campaign (e.g., aquiring rather than buying, etc.). What would be the easiest way to incorporate this into DH without doing too much violence to the system mechanically?

off the top of my head, I don't really see how the system would cause any violence to the core system mechanically. It is afterall a derivative of the Influence system already in place. You'd just have to give the players an Influence rating and tell them to have at it.

Agree that it should work fine pretty much unmodified. The only thing to figure out is how much influence to let them have; what are the Acoltyes playing as? New recruits? Established agents? Nearly Inquisitors themselves?