1. Personaly i have 2 hours only. And i was asked very similar questions to those who has cpl and ppl. I think they will ask you a bit more in depth if you have a license. I am made to believe they focus more on the personal background quesionts, please be well prepared. Know yourself.
2. I would say it doesnt really matter, one or 2 hr is just fine. In the final interview I met a guy with only 1 hour, another with a ppl and the last one with cpl. We all get to the final stage. I would recommend reading more about aerodynamics, know the CX's fleet and the latest news of CX. (please change to KA if you are not CX's fans)
Good luck!