Answer to Question 1
The components in a communicating system talk to each other via a communication bus, so the zone control makes decisions based on real time data. The zone control adjusts the airflow to meet the zone demands and also adjusts the system capacity to match system load.
Answer to Question 2
Flares for R-410A systems have a larger cone. The flare fittings are heavier wall and have a larger chamfer to accommodate the larger cone.