If you want to play music on Kodi and give voice commands to do it then you absolutely must have that music scanned into your Kodi library. Period. It does not matter where the actual files are stored on your network but they must be scanned into your Kodi library.
Then you can generate XML using the xJson plugin.
Some things like actors are probably not being scanned in the xJson plugin. In order to get more than just the basic xml scanned then you will need to use the xSql plugin. You need to make your database files accessible to your windows PC and then enter the correct path to the files in order for this to work. If it does not work then it means that you either entered the wrong file path, or you did not set up your network share correctly.
Simple PVR commands like channel up and channel down are included in the default configuration for Isengard in version 2.2.1.6 of VoxCommando. Scanning the names of your TV channels also requires you to use the xSQL plugin to generate XML.