I'm about to redesign a Wordpress-based site with an eye toward SEO and surfacing older content, and there's a bit of a situation I'm on the fence about. There are maybe a dozen main categories and a hundred+ subcategories (most of which have only a post or two). The permalink structure is /category/postname.

I know how to move things around without breaking incoming links, but I'm undecided if I should. What do you think... move posts into logical parent categories for better organization? Would that help or hinder SEO efforts? I'm leaning toward leaving things as they are because it gives us more words in the URL, but I'm a little concerned that Google might see that as keyword abuse or something. Would it make sense to move the posts into parent categories and then use the old subcategory labels as tags?