Hi,
Warnings are not errors. These indicate just information Google would like to know on your products.
For example, as long as you provide a price for your products, Google wants to know the date until which the price provided is valid.
That way, their crawler knows that after this specific date, it has to recrawl that page to get the new price.
Similarly, if it finds that the page is a product page, it wants to get reviews and ratings (votes). Fixing these warnings is possible by having votes/comments posted after activating the corresponding settings in the HikaShop configuration. But if you don't want your customers to vote/comment on your products, then of course, you can't provide that information.
So basically, you can just ignore these. They won't impact the indexing of your products.