custom shopping cart

Shopping cart designed in a fresh install of WordPress / Genesis (child theme TBD) and WooCommerce
The shopping cart must be mobile responsive and function like my current Advanced Tool site: weblink to cart: http://www.advancedtool.com/end-mills/. Another example of this type of cart is here: https://www.atlascuttingtools.com/categories/end-mills/
In a nutshell, there are several different categories with additional drill down categories options that lead the customer to a grid style format for purchasing. http://www.advancedtool.com/end-mills/?category_id=122. The EDP# will also have a hyperlink in the grid that will display the item on its own page (I believe this is the standard woocommerce method of displaying items).
All chart information including image name will be supplied via an excel file spreadsheet, there are just under 1200 products total.

Other requirements:
I need to be able to set up specific customers with a % discount off of list price, they will need user password and log in ability so that their discount is applied.
There needs to be a search function similar to the Atlas search ability: http://www.atlascuttingtools.com/findmytool.php
I need the ability to later on do a mass price change via excel file import or something similar.
I will need documentation of the file structure and layout so that any other developer would understand where to find necessary areas should something break down the road.
This full shopping cart must be able to handle updates inside of WordPress, Genesis, and the plugins used to create this cart without breaking.
Shipping rate parameters and our tax code will need to be set up in Woocommerce, as well as a working connection to my Authorize.net gateway for credit card processing.
I will also need to be shown how to gain access to everything on the back end.