I might have misunderstood the question but what really matters is how you get to the content not necessarily the URL structure (relevancy required - no spam please).

Given this "freshness" aspect i.e. recent links / social shares will enhance the opportunities for this particular page to appear in the results (given other SEO boxes are "ticked"), the "extra" folders will not matter.

Hi, I think as you offer translation services, you have an especially strong need to have real people translate the relevant parts of the website (rather than software).

With regards to geo-targeting in webmaster tools. The suggestion is to geo-target the /es folder rather than just a page. So all the Spanish elements are targeted within that folder.

Resources permitting and having a good understanding of your / your client's markets I would suggest extending this to the other Spanish speaking countries you are targeting. The nuances of language are enough to warrant this and it is an opportunity to demonstrate expertise in translation.

If using an iframe plugin from FB it is not actually on your site

FB has MASSIVE duplicate content issues 'cos it's a poorly constructed site, so don't worry, be happy

Use FB to drive traffic to your site. Always put quality content on your site (and get it indexed) b4 placing on FB (if at all - users will come to your site if teaser info on FB is good enuff)