Unembedding oUF
 

As the title says, how would I take a layout and make it dependent on oUF that is not embedded with the addon?

When people embed oUF all they are doing is copying the entire addon minus the .toc file and placing it within their addon and then adding the files to their toc file so oUF will load. All you would need to do is delete this folder and then add the following line to your .toc file.