Anton Paramonov

Pretty simple plugin for disable:
<ul>
<li>the XML-RPC on a WordPress site running 3.5 or above</li>
<li>new emoji functionality in WordPress 4.2</li>
<li>Posts and Comments general feeds</li>
</ul>
And remove:
<ul>
<li>WordPress genarator meta tag from HTML source page</li>
<li>link to wlwmanifest file from HTML source page (Windows Live Writer)</li>
<li>link to RSD EditURI from HTML source page</li>
<li>X-Pingback from HTTP headers and pingback_url in HTML source page</li>
<li>shortlink from HTTP headers and HTML source page</li>
</ul>
Translated on English, Russian and Ukraine languages.

YaBlog

Allows administrators to globally disable XML-RPC, new emoji functionality in WordPress 4.2, wp generator, wlwmanifest, RSD EditURI and rss/feeds on t …

Sumit Singh

Milankumar Sanandia

This plugin allows administrators to globally disable comments on any post type (posts, pages, attachments, etc.) so that these settings cannot be overridden for individual posts. It also removes all comment-related fields from edit and quick-edit screens. On multisite installations, it can be used to disable comments on the entire network.
Additionally, post-comment-related items can be removed from the Dashboard, Widgets, the Admin Menu and the Admin Bar.
Important note: Use this plugin if you don’t want comments at all on your site (or on certain post types). Don’t use it if you want to selectively disable comments on individual posts – WordPress lets you do that anyway. If you don’t know how to disable comments on individual posts, there are instructions in <a href="https://wordpress.org/plugins/disable-post-comments/faq/" rel="ugc">the FAQ</a>.
If you come across any bugs or have suggestions, please use the plugin support forum. I can’t fix it if I don’t know it’s broken! Please check the <a href="https://wordpress.org/plugins/disable-post-comments/faq/" rel="ugc">FAQ</a> for common issues.
Want to contribute? Here’s the <a href="https://github.com/sssumitsingh/disable-post-comments" rel="nofollow ugc">GitHub development repository</a>.
A <a href="https://github.com/sssumitsingh/disable-post-comments" rel="nofollow ugc">must-use version</a> of the plugin is also available.
<h3>Details</h3>
The plugin provides the option to completely disable the commenting feature in WordPress. When this option is selected, the following changes are made:
<ul>
<li>All “Comments” links are hidden from the Admin Menu and Admin Bar;</li>
<li>All comment-related sections (“Recent Comments”, “Discussion” etc.) are hidden from the WordPress Dashboard;</li>
<li>All comment-related widgets are disabled (so your theme cannot use them);</li>
<li>The “Discussion” settings page is hidden;</li>
<li>All comment RSS/Atom feeds are disabled (and requests for these will be redirected to the parent post);</li>
<li>The X-Pingback HTTP header is removed from all pages;</li>
<li>Outgoing pingbacks are disabled.</li>
</ul>
Please delete any existing comments on your site before applying this setting, otherwise (depending on your theme) those comments may still be displayed to visitors. You can use the Delete Comments tool to delete any existing comments on your site.
<h3>Advanced Configuration</h3>
Some of the plugin’s behaviour can be modified by site administrators and plugin/theme developers through code:
<ul>
<li>
Define <code>DISABLE_COMMENTS_REMOVE_COMMENTS_TEMPLATE</code> and set it to <code>false</code> to prevent the plugin from replacing the theme’s comment template with an empty one.
</li>
<li>
Define <code>DISABLE_POST_COMMENTS_ALLOW_DISCUSSION_SETTINGS</code> and set it to <code>true</code> to prevent the plugin from hiding the Discussion settings page.
</li>
</ul>
These definitions can be made either in your main <code>wp-config.php</code> or in your theme’s <code>functions.php</code> file.

Disable Post Comments

This plugin allows administrators can disable wordpress all post type comments on their site and also can be disabled specific post type.

YaBlog vs Disable Post Comments