Hari's Z-Wave device is a DCE device, and thus should be used within the construct of DCE.
This means you would need,
* DCE Router
* MySQL for the database
* Lighting Plugin (to provide some abstracted functionality)
* Climate Plugin (same thing)
* Security Plugin (same thing)
* The ZWave device template in the database
* the templates for each child device
You can then build a complete system around this, using LibDCE to send messages to the lighting plugin and to the ZWave device.
You get in return:
* A stable architecture
* an extensible architecture
* interoperability with our stuff
or, you could just reinvent the wheel like any other programmer...but in my view that would be retarded.