If you want to customize the module, you could do it by using a child theme. For instance if you want to create a custom version of Module 13, you need to create file or copy from the original: jnews/class/Module/Block/Block_13_View.php into jnews-child/class/Module/Block/Block_13_View.php
Then do the customization in the child theme.
Regarding WPBakery Page Builder license, I can be sure you have the FULL version of the plugin. You can use the plugin with or without the activation, and there is no feature reduction that you can utilize it in composing page with JNews. The activation is mostly for enabling the auto-update feature, you might encounter issue if you update version very early before JNews supported the version.