How to remove certain meta tags?
This is displayed in html.tpl.php in the variable $head. $head is added to the variables in template_process_html by using drupal_get_html_head(). In that function, you can see that hook_html_head_alter() is called.

There can you remove these.

However, note that these links can be important for SEO, to avoid that a search engine thinks that you have duplicate content on your site, if for example a node is available through node/nid and the alias.