Hi,
1. You have to do a translation override and not a view edition for that 
2. Sure, Please delete the code:
if(empty ($this->element->characteristics) || $this->params->get('characteristic_display')!='list'){ ?>
<div id="hikashop_product_quantity_main" class="hikashop_product_quantity_main">
<?php
//LAYOUT quantity
$this->row = & $this->element;
$this->ajax = 'if(hikashopCheckChangeForm(\'item\',\'hikashop_product_form\')){ return hikashopModifyQuantity(\'' . $this->row->product_id . '\',field,1' . $form . ',\'cart\'); } else { return false; }';
$this->setLayout('quantity');
echo $this->loadTemplate();
?>
</div>
<?php } ?>
And add:
if(empty ($this->element->characteristics) || $this->params->get('characteristic_display')!='list'){ ?>
<?php
//LAYOUT quantity
$this->row = & $this->element;
$this->ajax = 'if(hikashopCheckChangeForm(\'item\',\'hikashop_product_form\')){ return hikashopModifyQuantity(\'' . $this->row->product_id . '\',field,1' . $form . ',\'cart\'); } else { return false; }';
$this->setLayout('quantity');
echo $this->loadTemplate();
?>
<?php } ?>
Right after:
if ($this->params->get('show_price')) {
$this->row = & $this->element;
$this->setLayout('listing_price');
echo $this->loadTemplate();
}