I decided to group together everything that is scattered in 2-3 prior posts into one post here with the current status of my question, to make it easier to follow.
I'm just looking to make a nice smooth intuitive site that has robust search and filtering of "products" sorted by various criteria, using dropdown menus with categories and subcategories with proper hierarchy.

Here is where I am at:

I have KickStart 2 installed on a server.

We managed to disable the KS2 menu and replace with a Superfish menu that functions great. But I have spent days trying to understand how to do the simplest thing that almost every major commerce site (and others) seem to do easily.
Say you have a Menu across your home page on top with various holiday sweets...

Pies - Cookies - Candy

Now, when you hover on, say, Pies for example, it will drop down into subcategories of:

-Fruit
-Cream
-Other

Now say, you hover on Fruit, it will slide out a third subcategory of various fruit pies, as follows:

PIES
. -Fruit>>--Apple
. --Cherry
. --Pumpkin

Here are the issues: First, this seems to almost be possible, except when you CLICK to go to any category you get *no pies* displayed until you get to the exact subcategory the pie is in. The way it *should* work is when you click on "Pies", you see *all* pies on the site (Fruit, Cream, and Other) all grouped together. If you let it drop down and click on Fruit, you then should see ALL fruit pies on the site, and none of the others. If you let it go to the third refined subcategory, and click on a specific fruit, like pumpkin, you then should see just the pumpkin pies on the site.
All of the tutorials I see go through these complex adjustments and Views and taxonomy relationships, and never seem to do this.

Secondly, the URL in the browser should be intuitive, like if you are viewing pumpkin pies, your URL would look like www.pies.com/products/pies/fruit/pumpkin/

*and*, your Breadcrumb display should be, obviously: Home > Products > Pies > Fruit > Pumpkin

Sounds so easy, right? Well days of pulling my hair out and getting nowhere, trying to solve this!
Its got to be so simple, as its basically how *all* websites work, but somehow I must be missing it!
I set up vocabularies with terms and subterms, but it doesn't translate that way into the menu, where it works in a hierarchical way.
Can anyone help with this?

Isn't this the simplest thing in the world? Why have I been struggling for weeks trying to wrap my head around how to make Drupal (Kickstart 2) do this? It should be a default! I've watched hours of these video tutorials, explaining about hierarchical categories that get so complex, and only manage to set things up to show links of subcategories, but you get no products until you get to its exact category. That's *not* how most sites work at all. Clicking on "Pies" should result in display of thumbnails and listing of *all pies*. Clicking a parent category should always display all of the products in its subcategories, like a filter. Filtering should also be available in the left sidebar. Is this really that difficult to set up with Drupal KS2?

Update: Someone finally found a site using Drupal 7 which comes the closest to doing what I am trying to do, but how do you do it?
https://www.avcdistributor.com/terms-conditions

That site is pretty much exactly what I am trying to do! The left sidebar refinement filters as well. The breadcrumbs work correctly there, too!
The only thing that is out of sorts there is that the URL's aren't reflecting the hierarchy correctly, as the breadcrumbs do (some of the subcategories, the URL treats as a main category, directly off of " /store ", but this is a minor issue, I suppose). So, it *is* possible with Drupal 7, but I wish there was a template to do exactly this. Its taking forever to figure out.
What I have done in Kickstart 2 is set each main category as a vocabulary, and each subcategory as a term, and each child category of that, a subterm of that term, and so forth.
On the front end, it seems to still only display the item if the exact category is clicked that it is in, but fails to show the item if any parent category is clicked. (Therefore, not true hierarchy). The tutorials explaining how to manipulate the Views gets even more complex, and only seems to result in displaying the subcategories, rather than the *items* in the subcategories. The site linked above is pretty much what I am trying to do,. the question is just, how to do it the simplest way possible. I've already spent weeks on it all, its driving me crazy.