Posse: a few quick questions

Hi! I just have a few questions about posse

  1. What exactly does it cover.

  2. Can you also apply to Questbridge/at what point would you have to decide between the two?

  3. May you choose your interview dates, for example if you would like to be interviewed in September rather than August

  4. How much do grades/ECs matter?

  5. Any tips or other information would be appreciated