There should be no concern at all. Mark is in full control this time so people should enter with confidence.
The hunt for talent is global, so anyone from any country can enter.
However, you have to be over 18 in order to enter, so you have to be over 18 as of today. Unfortunately you'll have to wait, but this is going to be an annual activity going forwards so keep drawing and we'll look forward to your entry next year.