Hi QuantumWarp,
Thanks for interest in my works. Let's say, whmcs is a good billing system, but has no any ability on content management. If you use whmcs only manage your bills, that's fine. However, that could be a nightmare if you use whmcs to manage your website. Without the ability on content management means you've hard-code your template files line by line for any changes. Meanwhile, WordPress is the most popluar cms on the market for years. Not only because how that friendly to maintenance or how that search engine friendly. But you can found thousands of useful plugins for WordPress which can help improve the system whatever you want.
The bundled package includes one WordPress theme and the WHMCS template 'Responsio+'. You can use it as an out-of-the-box solution to setup your website by integrate WordPress and whmcs. Without the Responsio template, the standalone WordPress theme is no different than all other WordPress theme. That doesn't has any ability to connect WordPress with whmcs. Usually my customers take the standalone theme because they already has the Responsio template but just want to have a new look.
In fact, the Responsio template can run standalone as a pure whmcs based template without WordPress.
-> http://demo.whmcsconnect.com/whmcs/clientarea.php?theme=standalone
Or you can integrate it with any other third-party themes by purchase the optional add-on imSync. Enclosed is another few demos which show you how Responsio work with other third-party themes :
http://demo.whmcsconnect.com/wordpress/enfold/
http://demo.whmcsconnect.com/wordpress/startup/
http://demo.whmcsconnect.com/wordpress/avada/
http://demo.whmcsconnect.com/wordpress/twentyfourteen/
http://demo.whmcsconnect.com/html/fivelayer/
http://demo.whmcsconnect.com/testdrive/the7/