Quote -
Tech questions asked, is it handling big jets/Cathay type questions -
About 15 Tech questions, and none that I remember from my CX and EK days were similiar which was refreshing. Common sense ones thank god! but each person had a different exam and you'll just have to be expereinced to get the answers I guess or read as many books as you can, sry don't know where to start re: this.
-Pysch test, recommended preperation -
I have recommended to others to do a course and well worth the money. They were similar again to Q, CX and EK but as the test went on they got harder. 4 hrs at home followed by a confirmation 30-40 min test at DJ's, The 3rd party can tell if the person at home actually did the test at DJ's so look out.
-General interviewer questions -
Again pretty much STD, why here and tell me how you got to this stage in your career etc etc. Again, a course will well prepare you for this and many other well known Co's. You must be honest as a 3rd party will check trust me and so they should.
-Group exercise what to expect -I must say, this was actually harder than EK's (which I passed) and you really can't practice because you are who you are and nothing can train you for that. There are about 4-5 managers watching (depending on class size) and no one is appointed head, you must interact but don't over do it either. Again, this is where they join the dots, they compare your Phy tests along with interview and see if your the name on the application. Hell I know heaps in the past (not at VA) who act this part well only to be tripped up when they finally join so VA are pretty weary of this and again they should I guess because 14 hrs is a long time between stiff drinks 
Does this help 
and good luck 