Can and how can these be added onto a Vera3
Yes the GE/Jasco 45603 can very easily be added to vera.
Go to Devices >> Add Devices and click the “Add ZWave devices, like light switches, door locks, thermostats, etc.” Add button
Then follow option 1 or 2 … push the button on the unit to include it into the ZWave network.
Then you want to probably test it it and see if vera can control it from the web interface.
If that works, include your switch in a scene(s) and pick the triggers you want to control the light. So one scene will turn it on, another will turn it off. The triggers control when that happens.