Always show next page link in pager
The line

if ($page_new[$element] == ($pager_total[$element] - 1)) {


Will never fire because of the earlier line: 

if ($pager_page_array[$element] &lt; ($pager_total[$element] - 1)) {


So if the current page is equal to (or higher) then the last page it will skip the whole code. 

Try removing that line (and the corresponding closing bracket }).
I hovever don't know if it will keep working then because the following function seems to be assuming it can never load a pager higher then the current page. So prepare for some unexpected behavior.

$page_new = pager_load_array($pager_page_array[$element] + $interval, $element, $pager_page_array);