Student Exchange Program Scholarship

Hi.I'm planning to apply this scholarship for a student exchange program.It's the YES scholarship and it is a merit based scholarship awarded to outstanding students who obtain good grades and show a strong interest in the USA.However,there are only 40 of them.
So,these are the criteria that I have:

-Obtained a credit for the Australian Mathematics Competition

-I'm a Head Student

-Straight A student- I was the class valediction for 2 years

-took part in the Chess Competition(district level)-under the Indoor Games club

-1st place in the Moral and Ethics quiz(district level)

-Active St.John member-qualified first aider(with certificate)

-Got a certificate for reading the most books

-Vice Secretary of the English Language Society(2004/05)

-Attended School Integration Camp

-Full attendance to school for this whole year

-took part in the National science Challenge(national level)-had to stay for 1 week in a university and conduct a university level research(I'm 16 by the way)

-Attended Creative Writing Course

-A volunteer at the SPCA(Animal Shelter)

-Currently learning French(Delf A1)

Interview skills
-I attended an interview to qualify me to attend a camp and the interviewer told my teacher I could really speak my mind and she seemed impressed.She asked me questions on teenage problems and about the country's astronaut.I gave my opinion,Finally,I got accepted to that camp.I also went for the prefect interview in school and that's about it)

So,do you think I can ace that interview?Most importantly,do you think I can get that scholarship?The scholarship selection depends a lot on the interview though.

Also how do I improve my interview skills?Because if I were to practise with someone,it's quite unlikely that someone would know what the interviewer would ask in the interview?