WS Header Cleaner plugin clean unusable links from header & footer.
Site Language Definition is a simple plugin for forcing the web browser to know what language your site is in.
Remove Feed Links is a simple plugin for removing feed links from the head of your web site.
Adds easily the Google-specific metatag "news_keywords" with Post Tags into wp_head().
Useful Tweaks is a powerful “all in one” tweaks plugin. 50+ functions help you configure your system in one plugin.
Tweak the performance and automated settings of your WordPress wsite by checking or unchecking the numerous options on the settings page.