Business letters in Germany and other european countries

In my previous Blog post i was talking about business letters in China and how important it is to have knowledge about the cultural attitudes. In comparison, Business letters in Germany are written in a similar way like North American letters. They seem to be very informal. However, business contacts are more formal. They normally address each other with titles and last names even if they have known each other for a long amount of time. The letter introduction in a German business letter generally refers past events that have happened such as meetings or other subjects. Furthermore in french businesses it would be inappropriate to begin a letter with a request before giving an explanation of the problem or situation. French business letters include a very respectful closing such as " of my most respectful wishes".
Foreign business messages contain passive voice constructions and compliments towards the business or organization. The format in foreign letters might differ from North American messages. Usually letters from North America are typewritten and single spaced, while other countries may prefer handwritten letters. In addition to, the foreign addresses might be organized in a different way than North American addresses. The structure is different in comparison. Furthermore, dates and numbers also have a diverse structure and can be confusing for people. A German date would look like this: 5th of August 2014 or 5.8.2012 while the North American style would be August 5, 2014 or 8/5/2014.

Does anyone know any European languages other than English? And if so, what do you find the most difficult. For myself, i speak French, Spanish and German and i find that the differences are mostly in the grammar and formality. While English only has the word "you" referred to everyone including business contacts, in Germany for example, if you speak or write to people you work with or people you do not know that well, you use a more formal salutation. Same in Spanish and French.
References:
YouTube http://www.youtube.com/watch?v=pMH5wWYRdpI
Business Communication Text Book, International messages