Hi,
Allowing for the edition of the custom item fields during the checkout is not possible.
It would require complex coding to allow for that.
Adding text after the custom fields can be done with a bit of coding in the file show_block_cart via the menu Display>Views.
It's much easier than your first request. The fields are displayed there with that code:
foreach($this->extraFields['product'] as $field) {
$namekey = $field->field_namekey;
?> <td data-title="<?php echo $this->fieldClass->trans($field->field_realname); ?>" class="hikashop_cart_product_field_<?php echo $namekey; ?>">
<?php
if(!empty($product->$namekey)) {
echo '<p class="hikashop_checkout_cart_product_'.$namekey.'">' . $this->fieldClass->show($field, $product->$namekey) . '</p>';
}
?>
</td>
<?php
}
So you'll have to add your custom code in there.