WordPress Small Snippets - Clean Admin Panel

gistfile1.php

<?php
// Remove columns from Posts admin
add_filter('manage_posts_columns', 'my_posts_columns');
function my_posts_columns($defaults) {
    unset($defaults['comments']);
    unset($defaults['author']);
    unset($defaults['tags']);
    //unset($defaults['date']);
    return $defaults;
}

// Remove columns from Pages admin
add_filter('manage_pages_columns', 'my_pages_columns');
function my_pages_columns($defaults) {
    unset($defaults['comments']);
    unset($defaults['author']);
    //unset($defaults['date']);
    return $defaults;
}

// Remove columns from Media admin
add_filter('manage_media_columns', 'my_media_columns');
function my_media_columns($defaults) {
    unset($defaults['comments']);
    unset($defaults['author']);
    //unset($defaults['date']);
    return $defaults;
}

// Remove Links from admin
add_action( 'admin_menu', 'remove_links_menu' );
function remove_links_menu() {
     remove_menu_page('link-manager.php');
}

// If more than one page exists, return TRUE
function show_posts_nav() {
	global $wp_query;
	return ($wp_query->max_num_pages > 1);
}

// Add support for page excerpts
add_post_type_support( 'page', 'excerpt' );

// Remove inline .recentcomments styles
add_action( 'widgets_init', 'my_remove_recent_comments_style' );
function my_remove_recent_comments_style() {
	global $wp_widget_factory;
	remove_action( 'wp_head', array( $wp_widget_factory->widgets['WP_Widget_Recent_Comments'], 'recent_comments_style'  ) );
}

// Remove all default widgets
add_action( 'widgets_init', 'my_unregister_widgets' );
function my_unregister_widgets() {
        unregister_widget( 'WP_Widget_Pages' );
        unregister_widget( 'WP_Widget_Calendar' );
        unregister_widget( 'WP_Widget_Archives' );
        unregister_widget( 'WP_Widget_Links' );
        unregister_widget( 'WP_Widget_Categories' );
        unregister_widget( 'WP_Widget_Recent_Posts' );
        unregister_widget( 'WP_Widget_Search' );
        unregister_widget( 'WP_Widget_Tag_Cloud' );
        unregister_widget( 'WP_Widget_RSS' );
        unregister_widget( 'WP_Widget_Meta' );
        unregister_widget( 'WP_Widget_Recent_Comments' );
        unregister_widget( 'WP_Nav_Menu_Widget' );
}
?>