Custom Role for CPT Only

I have removed admin specific capabilities for the custom role however they can still delete admin published listings.

I only want people with the custom role of submit_listing to be able to submit and edit own listings, not delete or edit listings from admin, author or editor.

add_action( 'admin_init', 'add_custom_role_capabilities', 999 ); 

function add_custom_role_capabilities() {

    // Don't lock admins out
    $admins = get_role( 'administrator' );

    $admins->add_cap( 'publish_listings' ); 
    $admins->add_cap( 'edit_listings' ); 
    $admins->add_cap( 'edit_others_listings' ); 
    $admins->add_cap( 'delete_listings' ); 
    $admins->add_cap( 'delete_others_listings' ); 
    $admins->add_cap( 'read_private_listings' ); 
    $admins->add_cap( 'edit_listing' ); 
    $admins->add_cap( 'delete_listing' ); 
    $admins->add_cap( 'read_listing' ); 

    // Does our custom role exist?
    $submit_listing = get_role( 'submit_listing' );

    // Nope? Let's create it
    if ( ! $submit_listing )
        $submit_listing = add_role( 'submit_listing', __( 'Submit Listings' ) );

    // Add core capabilities
    $submit_listing->add_cap( 'read' ); // admin access
    $submit_listing->add_cap( 'upload_files' ); // featured images

    // Add listings capabilities
    $submit_listing->add_cap( 'edit_listings' ); 
    $submit_listing->add_cap( 'delete_listings' ); 
    $submit_listing->add_cap( 'read_private_listings' ); 
    $submit_listing->add_cap( 'edit_listing' ); 
    $submit_listing->add_cap( 'delete_listing' ); 
    $submit_listing->add_cap( 'read_listing' ); 

}

Also note the following post type args :

'capability_type'   => array( 'listing', 'listings' );
    'map_meta_cap'      => false;
    'capabilities' => array(
                'publish_posts' => 'publish_listings',
                'edit_posts' => 'edit_listings',
                'edit_others_posts' => 'edit_others_listings',
                'delete_posts' => 'delete_listings',
                'delete_others_posts' => 'delete_others_listings',
                'read_private_posts' => 'read_private_listings',
                'edit_post' => 'edit_listing',
                'delete_post' => 'delete_listing',
                'read_post' => 'read_listing',
            );

    return $args;