You do not use a QNH for Flight Levels; you use an altimeter setting of 1013 - I think you are getting the two terms confused.
An Air Traffic Controller will tell you to use a QNH of (for example) 1005 meaning the altimeter will read altitude about sea level. If the Controller says QFE 1005, your altimeter will read height above ground.
I do know the other answers but, as you have paraphrased the questions and not necessarily given all the correct multi-choice answers, I would be reluctant. As you can guess, the exact wording is very important. In addition, it is unlikely that you will get the same questions when you resit.
You could order Trevor Thom's Air Law book online and could be with you in a few days if that helps!
Cheers
Whirls