Removes Comments from WordPress admin, inc. Admin Bar, Dashboard, column in Posts/Pages lists, and meta box in Edit Posts.

wp-remove-comments-supports.php

<?php
/*******************************
 =Comments: Remove
 ******************************/
/* Remove comments support from native post types
 *
 * Removes Comments column from admin post lists and Comments meta-box from Edit Post.
 */
function headecon_remove_comments() {
    remove_post_type_support( 'post', 'comments' );
    remove_post_type_support( 'page', 'comments' );
    remove_post_type_support( 'attachment', 'comments' );
}
add_action( 'init', 'headecon_remove_comments', 100 );

/* Remove Comments menu page link in Dashboard sidebar
 *
 * Menu page still accessible:
 * @link /wp-admin/edit-comments.php
 */
function headecon_remove_menus(){
  remove_menu_page( 'edit-comments.php' );
}
add_action( 'admin_menu', 'headecon_remove_menus' );

/* Remove comments menu page link in admin bar */
function headecon_admin_bar_rm_menu() {
    global $wp_admin_bar;
    $wp_admin_bar->remove_menu( 'comments' );
}
add_action( 'wp_before_admin_bar_render', 'headecon_admin_bar_rm_menu' );

/* Remove HTML head link to /comments/feed */
add_filter( 'feed_links_show_comments_feed', '__return_false' );

/* Jetpack Carousel: CSS to Hide Comment Form, Link, and "Loading" message 
#jp-carousel-comment-form-container,
div.jp-carousel-buttons a.jp-carousel-commentlink,
div.jp-carousel-image-meta,
#jp-carousel-comments-loading { display: none !important; }

.jp-carousel-buttons { padding: 0 !important; }
*/
?>