Call to a member function main() on a non-object

I’m trying to use wordpress for my site, however I just want to use the back end for users to edit my content and completely customize the front end. Rather than editing templates, I want to include wordpress in one of my classes and basically remove the wordpress header/footer.

I’m new to wordpress, so anyone else’s experience or feedback on how I’m doing this would be greatly appreciated.

<?php
class GamerSourceApplicationSiteArticleView extends GamerSourceApplicationSitePage {
	/*===========================================*/
	/* Public Functions
	/*===========================================*/
	function authenticate () {
		return true;
	}
	function show () {
		/**
		 * Front to the WordPress application. This file doesn't do anything, but loads
		 * wp-blog-header.php which does and tells WordPress to load the theme.
		 *
		 * @package WordPress
		 */

		/**
		 * Tells WordPress to load the WordPress theme and output it.
		 *
		 * @var bool
		 */
		define('WP_USE_THEMES', true);

		/** Loads the WordPress Environment and Template */
		require($this->tru->config->get("root.path")."/author/wp-blog-header.php");
		// end word press

	}
//..... class continues, but this is the only function that "shows" content

Through doing that, I originally had an error with set_prefix because $wpdb was not global. So I changed my wp-settings.php to global it and it works. However I”m now receiving the following error:

Fatal error: Call to a member function main() on a non-object in C:\wamp\www\gamer-source\author\wp-includes\functions.php on line 1111

Line 1111 is `function wp( $query_vars = ” ) {
global $wp, $wp_query, $wp_the_query;
$wp->main( $query_vars ); //line 1111

if( !isset($wp_the_query) )
$wp_the_query = $wp_query;
}`

Any thoughts?