You are running as root, why ?
You should install it in the ~/.node-red directory
The openzwave node requires the node-openzwave library to be installed/compiled first. Did you read the documentation ?
This package has one sole dependency: node-openzwave-shared. This is a fork of node-openzwave that links to OpenZWave as a shared library , therefore you need to have the OpenZWave library installed in your system beforehand , using the operating system's package manager, or by compiling OpenZWave yourself.