trying to add custom landing page to Twenty Eleven- can’t get rid of Twenty Eleven header/container? [duplicate]

as you seem to be using a page template, you can edit this even more and directly integrate the essential header and footer code into that template;

have a look at this example I recently made up: http://pastebin.com/ZiteZrUX

<?php
/**
 * Template Name: Blank Page Template
 *
 * @package WordPress
 * @subpackage Twenty_Eleven
 */ ?>
<?php // essential code from header.php ?>
<?php
/**
 * The Header for our theme.
 *
 * Displays all of the <head> section and everything up till <div id="main">
 *
 * @package WordPress
 * @subpackage Twenty_Eleven
 * @since Twenty Eleven 1.0
 */
?><!DOCTYPE html>
<!--[if IE 6]>
<html id="ie6" <?php language_attributes(); ?>>
<![endif]-->
<!--[if IE 7]>
<html id="ie7" <?php language_attributes(); ?>>
<![endif]-->
<!--[if IE 8]>
<html id="ie8" <?php language_attributes(); ?>>
<![endif]-->
<!--[if !(IE 6) | !(IE 7) | !(IE 8)  ]><!-->
<html <?php language_attributes(); ?>>
<!--<![endif]-->
<head>
<meta charset="<?php bloginfo( 'charset' ); ?>" />
<meta name="viewport" content="width=device-width" />
<title><?php
    /*
     * Print the <title> tag based on what is being viewed.
     */
    global $page, $paged;

    wp_title( '|', true, 'right' );

    // Add the blog name.
    bloginfo( 'name' );

    // Add the blog description for the home/front page.
    $site_description = get_bloginfo( 'description', 'display' );
    if ( $site_description && ( is_home() || is_front_page() ) )
        echo " | $site_description";

    // Add a page number if necessary:
    if ( $paged >= 2 || $page >= 2 )
        echo ' | ' . sprintf( __( 'Page %s', 'twentyeleven' ), max( $paged, $page ) );

    ?></title>
<link rel="profile" href="http://gmpg.org/xfn/11" />
<link rel="stylesheet" type="text/css" media="all" href="<?php bloginfo( 'stylesheet_url' ); ?>" />
<link rel="pingback" href="<?php bloginfo( 'pingback_url' ); ?>" />
<!--[if lt IE 9]>
<script src="<?php echo get_template_directory_uri(); ?>/js/html5.js" type="text/javascript"></script>
<![endif]-->
<?php
    if ( is_singular() && get_option( 'thread_comments' ) )
        wp_enqueue_script( 'comment-reply' );
    wp_head();
?>
</head>

<body <?php body_class(); ?>>
<div id="page" class="hfeed blank-page">
    <div id="main">

<?php //end of essential header.php code ?>

<?php //essential code of page.php ?>

        <div id="primary">
            <div id="content" role="main">

                <?php while ( have_posts() ) : the_post(); ?>

                    <?php get_template_part( 'content', 'page' ); ?>

                    <?php comments_template( '', true ); ?>

                <?php endwhile; // end of the loop. ?>

            </div><!-- #content -->
        </div><!-- #primary -->

<?php //end of essential code of page.php ?>

<?php //essential code of footer.php ?>
    </div><!-- #main -->

<div style="clear:both;float:none;"></div>
<?php //to clear the floats and stretch the #page background to the bottom/// ?>

</div><!-- #page -->

<?php wp_footer(); ?>

</body>
</html>
<?php //end of essential code of footer.php ?>

this still contains the basic page loop, but you could replace that as well with some custom html/php code.