1. I think they favor abstract elements instead of monuments because it shows that theirs more to France than just monuments. Also because Euros are used all throughout Europe it doesn't favor just one country, it shows all of them off in their own special ways.
2. This new currency affects the rest of Europe by being all the same on one side so its fair then each country has a chance to show off what they have on the other side. It also makes each country's money unique even though its the same money. It helps the economy by each country producing their own money and having it be independent even though its the same thing.
3. Overall it affects the economy of the U.S. by making it easier for us to trade with Europe. Since a majority of Europe uses the same currency we can trade different items and make money off of them without worry of making less money in a different country.
In France a very common way to celebrate things is to have a meal together. It is also common to receive a small gift at the dinner from the guests as away of saying thank you.