Remove forum comment title
First install the devel module and then check the theme registry to see if the forum form is in the theme registry or not. for more information about registering a form visit this page. as an example to register the comment form you must use this code:

function YOUR-THEME-NAME_theme($existing, $type, $theme, $path) {
    return array(
           'comment_form' =&gt; array(
               'render element' =&gt; 'form',
            ),
       );
};


When checking the existence the form theme in theme registry make sure that you use the YOUR-THEME-NAME as administrator theme.

Now use the hook_form_id_alter to customize the form.to see the form elements write:

kpr($form);


now you can hide or change the order of form elements.   

Here is the video tutorial