OK Let's start again now that we know your hands are sort of tied - for now.
I would write some introductory copy for each category page and use it to help the visitor. For example:
Widgets Main Category
Add content to this page. Explain what to look for in a widget. How do I choose one? Should I shop by resolution, capacity, type? What are the differences between widget brands? Is one more "high end" and another more "entry level"? Where do I go from here?
- Widgets by Resolution
Add content to this page. Explain the differences between various resolutions. What sort of resolution should I be looking for if I want to do This type of thing Vs That type of thing? What resolution do I need for the types of things I want to do? How can I get the best resolution for my budget?
- 0.1 Resolution widgets
Add content to this page. What are 0.1 Resolution Widgets best for? What do they not do well? When should I go up to a higher resolution widget? Are these more entry-level? Are they designed to provide me with all of the features I need to get started with widgeting at a lower cost point? Show me the "value" of 0.1 widgets without making them sound "cheap". At the same time, if I need a higher resolution widget, point me to the next level up. - 0.2 resolution widgets
Add content to this page. What are the 0.2 resolution widgets good for? Why should I buy one of these instead of a less expensive 0.1 resolution widget? Do I need a 0.3 resolution widget, or will a 0.2 give me what I need? Should I be concerned with capacity and other options too?
- Widgets by Capacity So on and So Forth...
---- About 20 subcategories
eg. 1 capacity widgets
2 capacity widgets
- Widgets by Type
---- About 12 subcategories
So in the end you'll need to write about 55 pages of content for those three categories and their subcategories. You can probably knock this out in a week if you focus on this project. Just don't fill it with useless "SEO copy". Try to anticipate and answer a visitor's questions so they know what to do next.
Rel canonical (rel next prev doesn't seem to work well, though in theory it's supposed to) the paginated pages of each category or subcategory back to first page in that cat/sub-cat.
It is quite alright if the products listed in different categories overlap. Make sure that products which exist in multiple categories don't have multiple URLs going to them. This tends to happen when categories are put into the product page URL. If that is the case, we can discuss different ways to handle it, but I'll assume it's not an issue for now.
