Hi,
For the category_pathway, if you toggle the "simplified breadcrumb" option of the configuration, you won't have it anymore.
Regarding the producto/categoria part that you want to be dynamically replaced by the name of the category, there is no easy way to do it.
Either you use a third party SEF rewriting extension where you would specify alias URLs (it can be hard work if you have a lot of products), or you edit the file components/com_hikashop/router.php and add custom code in it to replace that part of the URL by the current category.