With regard to changing the portfolio to service (or something else) for the individual “portfolio” items, can you try changing the value of the slug parameter at line number 201 in the file {theme folder}/framework/presentation/custom-post-types.php from –
'rewrite' => array('slug' => 'portfolio'),
to
'rewrite' => array('slug' => 'service'),
and see if that makes a difference? For this change to reflect, you will have to manually go to Settings > Permalinks in WordPress Admin and refresh your permalink structure before your custom post type will show the correct structure.