1. Correct. There is no subdirectory support in the current version.
This may change in the future.

2. You will have to prepare your own samples and upload them via the media manager, where you can attach them to products so they can be previewed. FAQ: https://www.zen-cart.com/tutorials/i...hp?article=119
It's probably most cost-effective to prepare your own samples, rather than attempt to write code to do that on a webserver.