1.) The driver talks to the hub, you have to tell the driver the name of the scene. Yes the dealer would have to program new scenes.
2.) No
3.) No, c4 just executes the scene.
As someone who has a v2 hub and hunter Douglas PV shades, you made a big mistake. They are giant pieces of shit and almost daily don't execute a scene the same way the hub does. Very disappointed in the battery life of larger shades too... MAYBE 7-8 weeks just opening and closing vanes, not even rolling up or down.