File download link in the list

It's always possible if you can code it.
You will have to edit the file "listing_img_title" (if you use the default item box layout) of the view "product" via the menu Display->Views and add code to:
1. Load the files of each product from the hikashop_file table.
2. Display the files link based on the entries from that table for each product.

You can look at an example for point 2 near the end of the file "show" of the view "product".

You can do it in listing_div if you want.
the listing_img_title is the default item box template used to display each product on a listing. In each of your menus and modules, you can set that template and choose different item box layouts in the hikashop options of the menu/module.

So the listing file display the main information of listings like the title, the description of the current category if activated and then calls the layout file, listing_div or listing_table or listing_list based on what you configured in the options of the menu/module.
In listing_div, the listing of the products itself is displayed. You can see all the divs of the item boxes. And for each product box, it calls the item box layout to display the inside of the box for the current product of the listing being displayed.