Re: first contact with admission office
Luca, are you applying to a school in the US? I'm assuming yes, because of the question about the Common App.
Your letter contains far too much information this is not relevant. No one cares why you didn't do military service, though the fact that you spent 11 months in the US might help them know you are comfortable in an all-English enviornment.
I expect that the university Web site has a special section for foreign students. Have you studied the information found there? I wasn't aware that foreign students completed the Common App, but perhaps they do. However, I would expect that there would be information about how any credits earned at a university in your own country would transfer to their school.
I suggest you write a much shorter letter:
Dear Mr... or Ms... (as Ems has suggested, a real person, not a "sir or madam"):
My name is Luca [last name] and I am a 19-year-old Austrian student very interested in attending [name of university]. While I found a lot of useful information on the university Web site, I do have a question about my status as an applicant. I have completed a year of study at Vienna University of Economics and Law, so I am not certain whether I should I apply as a transfer student or as a freshman. I want to make sure I complete the application process correctly. I have an additional question if the answer is that I should apply as a freshman: Will any of my credits from my business classes at Vienna transfer to [name of University]? Thank you in advance for helping me navigate the application process.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.