Hi,
1. Export / Import should work if you're using HikaShop's. The prices, images, categories are listed in the CSV when exporting and the import is taking them into account. So it should normall work fine. Note that for images/files, the files themselves need to be copied via FTP as the data of the images/files itself is not in the CSV, only the path of the files/images.
If you're using PHPMyAdmin's export/import on the hikashop_product table, then it's normal you're missing all that as that data is in other tables: hikashop_file, hikashop_price, hikashop_product_category, etc. So if you want to do a PHPMyAdmin export/import, it's possible, but you need to export/import all the tables related to the product, not just hikashop_product
2. For 10-15 products, I wouldn't bother and just fill in the missing information in the backend interface. That way, you're guaranteed it will work like you want, and you won't have any surprise. And time-wise, it shouldn't change much.