Hi,
2. As I said, the extension I proposed should allow you to do that.
Also, in each product and category of HikaShop, you have a "canonical URL" field. If you enter in there the URL you want as the URL for that product / category, then when indexing the product / category page next time, Google will find the canonical URL and index it, regardless of what is the URL it used to find the product / category page.
3. Edit the file product / show.php via the menu Display>Views and at the beginning, you can add such code:
<?php
$doc = JFactory::getDocument();
$doc->setMetadata('robots', 'noindex, nofollow');
?>