The answer to your first question is no. Some of the biggest websites in the world started with supporting just one language. If you look at Google News today (you would agree with me that Google is pretty big) you will see there are many languages and locales that they still don't support, and the year is already 2014 - Denmark, Estonia, Finland, Luxembourg to name a few simply cannot be selected at http://news.google.com/.
To your question are the internationally-oriented formats you wrote universally understood, the answer would also be no. Many Americans would be confused seeing "USD" on their shopping cart, they would expect to see a "$" sign.
If you want to follow the formula of popular websites like Google, Amazon, and Stackexchange, get it right in one locale first and then expand the winning concept to other locales.