Simple SEO question about robots.txt

I was reading this guide:

http://boganmarketing.com/blog/ultimate-wordpress-robots-txt-for-silo-seo.html

I get most of it, but I don’t want to exclude wp-content/uploads directory , I don’t even see it in the robots.txt file he provided, so is it secretly there but I can’t see it?

Also, I heard that you should select only one category for a post (to prevent crawl of duplicated content). My theme requires a featured category, so what can I add on there to not crawl posts from the featured category?