OASC advice
My only advice for OASC at this stage would just to be yourself. Don't try and be someone else. Don't try and pretend to be what you think they want to see. The Boarding Officers just want to see the real you, and can see straight through anyone putting on an act.
Get to know the others in your group. Socialise in the evenings with your syndicate. That'll help you when it comes to the group exercises, and chances are you'll spend a lot of time sitting around talking to them if you get through to the end.