1. Cases for principal and dependent are processed independently based on five applications of my wife and myself.
2. Try to update USCIS the address in time or even ahead of time. My wife has moved from State A to my place (State B), and we both moved to State C in about 3 months. The address may not be able to be updated timely in both USPS and USCIS, esp. for my wife's. So one advice: call USCIS if you are not sure. We experience both bad and good reps in USCIS; but overall, it costs you nothing but a call.
2. Try to update USCIS the address in time or even ahead of time. My wife has moved from State A to my place (State B), and we both moved to State C in about 3 months. The address may not be able to be updated timely in both USPS and USCIS, esp. for my wife's. So one advice: call USCIS if you are not sure. We experience both bad and good reps in USCIS; but overall, it costs you nothing but a call.