What are my chances of getting into Yale, Penn or Duke?

It isn’t! I was just guessing, b/c those 3 states have the strongest populations with German ancestry (we used to live in one of them).

National level awards are a really strong asset for you (if your silver medal was at the upper level), and being on the national olympiad team is good enough for Cambridge University, so if you are at that level you should lead with it! It is objective evidence of your academic qualifications (plus your LoR from that subject should be outstanding).

I am sorry that you felt my response was unhelpful, but these questions were relevant to being able to say more:

Has your school ever sent a student to any of these schools? to any US school?
Will your advisor say that you are primus inter pares in your school, and back it up with examples of how extraordinary your are?

What do you feel makes you different, from the point of view of a university looking at you as a possible member of the community?

From here. I see your strong MUN background- but it is not a strong differentiator, as there are just so many students who also have one. You show initiative in your learning things on your own (such as French, guitar, singing), but what does that bring to the university? Note that I am not being critical of you or your achievements! This is a tough process you are embarking on, and figuring out the hard questions can help you figure it out.

Probably not a helpful addition to your application.