I have my products organized into two-level categories (beside the root category of course). I do have about 6 main categories, each one with 3-12 subcategories.
Most of products are added on a subcategory for each of main categories. So basically all products are on all top level categories (indirectly, belonging to subcategories of main categories).
I would like to forbid browsing through top-level categories because otherwise I will have each top level-category display nearly same products.The main problem was on breadcrumbs that are displayign the top level categories...
I have fixed this by making inactive all top level categories and having active just the sucategories.
But I still have some issues because some components (as HTML Sitemap) is relaying on browsing through active categories structure to list all products.