You need to look at it from CTC's point of view. One of the biggest concerns they have with any potential cadet is your motivation. New Zealand is a long way from home, the course is not easy and you will have non of your regular surroundings or friends/family around you when the going gets tough. So they want to see you demonstrate that you 100% want to do this career, as that is what will keep you going during the periods of the training that are tough and during the times you may doubt yourself - it happens to most guys on the course (whether they would admit it or not) and it's the fact that you are working towards your dream that keeps you going.
Don't get me wrong - if you love flying, want to be a pilot more than anything and have the right attitude towards the whole thing you will have a blast in a great country surrounded by like-minded people and you will come out of it with loads of good friends and the job you always wanted. But there were guys who quit while I was in NZ and it was because they were struggling with the course and it turned out they weren't that mad about being a pilot after all. That is what they will want to know from you - are you going to grit your teeth and deal with the low points or will you throw in the towell and cost them money in the process?
Look at it from their perspective and go into the interview knowing they want you to succeed and go to NZ, but only if they have no doubt you have the desire and motivation to last the course. Unless you feel ready and in a position to demonstrate this to them, delay your stage 3 for as long as it takes you to feel ready.
Best of luck to you, I'm sure you'll do fine
