Is there a Z-Wave product that will automatically turn on lights according to the time of year, gradually increasing toward summer and decreasing toward winter?
Yes any handheld controller with timers and an astronomical clock will allow you to accomplish your task. Controllers with astronomical clocks are sunrise and sunset aware because you program the location of the controller. The Leviton VRCPG-SG Vizia RF+ Z-Wave Remote Control with Timers provides user-level control of up to 128 devices, customizes 16 profiles and creates up to 255 scenes.
Please explain Z-Wave network security methods. Is my house secure against interference with the neighbor’s house, or from hackers?
When you setup a network the primary controller assigns a Home ID / Network ID and Device ID combination. Each Z-Wave device or chip has a unique address similiar to the MAC address on a network card. A network can only have one primary controller to include devices on/in the Z-Wave Network. A network can have multiple secondary controllers but the secondary controllers cannot add devices to the network. Locks and Lock Sets use the security class with AES128 encryption, thus your network and house are secure from neighbors and hackers.
I would like to control lighting from multiple locations. There would be several loads of several hundred watts. Can I buy four (or more) Z-Wave dimmer controls and have them all act in concert with one another? Also, do I need anything in addition to the dimmers to set up the system?
Yes you can do what you are looking to do. You’ll need both Dimmers and Handheld Controllersto set up the system. You will also need a Handheld controller to program the lights. Here are a few options to consider: