I'm using categories as my site's navigation. When you click a category, it only shows abbreviated posts with no image/media and text is truncated with [...]

is there a way to show the full posts, say 10 per page with a link to the next 10 older posts?

You can change that to show full posts at Atahualpa Theme Options -> Post or Excerpts

To change the amounts of posts per page see Site Admin -> Settings -> Reading (10 is the default)

There's always a link to the next posts. You can customize both the location and the text of those next/previous links at Atahualpa Theme Options -> Next/Previous Navigation

not sure how i missed that but thanks!