Hi,
Edit the file product / listing.php for your backend template via the menu Display->Views.
There, you'll have that line:
$img = $this->image->getThumbnail(@$row->file_path, array('width' => 50, 'height' => 50), $image_options);
You just have to increase the numbers there and it will increase the size of the images on the products listing in the backend.
For the other areas where you would like to do the same, it will be a similar modification. To know which view file to edit for which area, I would recommend to use the "Display view files" setting of the HikaShop configuration as explained here:
www.hikashop.com/support/documentation/1...-display.html#layout
Note that since you'll do these changes as view overrides, you'll keep these changes with future updates.