Is it possible to change the "add new comment" text on certain content types?
Check the roles/permission grid to restrict certain roles posting comments.

hook_node_view_alter(&amp;$build) would help to replace the label with your custom one.

e.g.

 function MODULE_node_view_alter(&amp;$build){
    if ( in_array($build['#node']-&gt;type, array('page')) )
    $build['links']['comment']['#links']['comment-add']['title'] = l('New Label', 'comment/reply/'. $build['#node']-&gt;nid);


There can be another easy way using String Overrides but it will not let you  do on specific content types.