I really honestly don't need all of this stuff. it is literally three products. they don't need categories, and they'll honestly never change. are there any recommendations you can give me?
I do not think that you have fully thought this through - -

There are many, many items that require attending to to offer a secure buying environment....

You need code to talk to and process Credit Cards - and code to enable a SSL layer for security/buyer confidence.

Customer order notification - order tracking and status update

Possibly currency conversion

etc., etc.

All these things are part of Zen Cart - for one product or 1,000's of products -

Don't short change your client in providing a less than complete solution