Hi,
1. It looks like this is working on your website.
When the website is in English, the categories module categories are in English:
take.ms/gzUZn
When the website is in Dutch, the categories module categories are in Dutch:
take.ms/pBc4D
2. If you activate the "force canonical URL on listings" setting, you need to configure the "canonical URL" field of the product page for each language, not only the alias field.
When you click on the flag to do the translation of the product when you edit the product, you should see that canonical URL field in the translation popup. If you don't, download again the HikaShop install package and install it on your website (we've added a patch for that in the last few days).