Hi Todd,
IMO you're intuition is right and Irving is saying a correct thing in the first point.
I too have noticed that you have pagination issues and that all the paginated urls have the same title html, substantially the same content. I suggest you to not let SE to index the paginated pages using "meta name="robots" content="noindex, follow". That way you will resolve a good number of duplication issues.
About thin content... yes, the content describing the categories and sub categories would not win the Pulitzer. Try to be more original and apply the content curation practice in order craft exceptional category description.
One thing I don't like of your site - without offence - is the fact that it is clearly an affiliate site: to click on a product and find myself directly sent to product page on the real site is not really giving me a great impression. Therefore, and you have nothing to loose after a 1 year buried in the serps, I would start reconsidering an integral re-definition of the site.