Rather old topic, but I'll throw in my 2 cents anyway.
DW2PDFs placeholders are defined in the 'action.php' located at lib > plugins > dw2pdf, they look something like this:
$replace = array(
'@PAGE@' => '{PAGENO}',
'@PAGES@' => '{nbpg}', //see also $mpdf->pagenumSuffix = ' / '
'@TITLE@' => hsc($title),
'@WIKI@' => $conf['title'],
'@WIKIURL@' => DOKU_URL,
'@DATE@' => dformat(time()),
'@BASE@' => DOKU_BASE,
'@TPLBASE@' => DOKU_BASE . 'lib/plugins/dw2pdf/tpl/' . $this->tpl . '/',
'@USER@' => $INFO['user']
);
I already added the last line
'@USER@' => $INFO['user']
. So when you place @USER@ in your PDF template, it gives you the name of the page's last editor. AFAIK there is no variable for the page creator...