TOPIC: PMP simulator and quiz....advise please

I'm going to activate my PrepCast simulator soon and I'm looking for the best approach to use the quiz and the tests, I'll start by taking the quiz related to the knowledge area which I'll review , the question is:
1.how much questions I should take for a particular area to be sufficient giving me an indication about my level?
2. is the excessive usage of the quiz question will affect the efficiency of the simulator question? i.e will that makes the questions to be repeated in the simulator or both has a different pools?