Don,
If you are studying the cathy prep stuff you are way way over preparing for the interview. The tech quiz is basic stuff, ie think what temp may visible moisture cause ice..etc. Not only that you can usually make it a group exercise.
Just come and be prepared to talk about your career giving examples of various leadership/crm/customer service qualities you've displayed in the past. Just sit back and do what pilot's do best, tell stories about yourself and you'll do fine.
Don't sweat tons of studying, i'm not the sharpest tool in the shed and i had no issues at all with minimal prep. Just come and enjoy the trip, meet some new people and take a look around EK and Dubai.