My suggest above works just fine in QAv1.3 but 'm not sure for QAv1.4. In version 1.4 I dont modify original code any more just do it all in advanced theme.
For AddThis stuff you should follow dofmike instruction or put this stuff below into your advance theme. Sure it works.
function q_view_main($q_view){
$this->output('<DIV CLASS="qa-q-view-main">');
/*-- Tenkana-QA Addon: Socialstream buttons --*/
$this->output('<div class="addthis_toolbox addthis_default_style">'.
'<a class="addthis_button_facebook"></a>'.
'<a class="addthis_button_twitter"></a>'.
'<a class="addthis_button_googlebuzz"></a>'.
'<a class="addthis_button_email"></a>'.
'<span class="addthis_separator"> </span>'.
'<a class="addthis_button_facebook_like"></a>'.
'<script type="text/javascript" src="
http://s7.addthis.com/js/250/addthis_widget.js"></script></div>');
/*-- ------------------------------------- --*/
$this->q_view_content($q_view);
$this->q_view_follows($q_view);
$this->post_tags($q_view, 'qa-q-view');
$this->post_avatar($q_view, 'qa-q-view');
$this->post_meta($q_view, 'qa-q-view');
$this->q_view_buttons($q_view);
$this->c_list(@$q_view['c_list'], 'qa-q-view');
$this->form(@$q_view['a_form']);
$this->c_list(@$q_view['a_form']['c_list'], 'qa-a-item');
$this->form(@$q_view['c_form']);
$this->output('</DIV> <!-- END qa-q-view-main -->');
}