Is there a way to get this rectified such that all products imported will appear on the appropriate category and sub-category

There are two ways to import products into categories and sub-categories.

1. To import products into the same categories as in the Amazon store with automatic creation of all sub-categories structure.

You might check these categories in the Categories option while you edit the product imported from Amazon store.

Import products

2. To import products into existing category. In this case you need to manually set the category. Please check the section "Import Params" in the "Import" page.

This article is related to the Amazon Products Manager Magento Extension.

This Magento extension allows you to easily import Amazon products into Magento.