Hey max,
first of all, its just the nice thing to do to fill out your COW info so we know more about what your working with, what kind of work you do and all that fun stuff. Sort of saves time as well.
Exposure has a lot to do with what your planning on doing with your footage. Some videographers who know they are going to go black and white will some times expose their video a few stops up to give the video a specific look. If magic bullet says that you shouldnt have any blown out areas, then it seems like the software will work best with video that falls in the proper 7.5 to 100 IRE range on your vectorscope.
Zebra lines can be a great handy tool… I usually have mine set to 100 IRE. It works for me. The idea is that you will be able to see what your camera thinks is hot. Some people think that you would turn on the zebra lines to see where the image is ‘over exposed,’ but is really there to show you where the hottest parts of the image are located. Those people’s footage came out really dark because obviously they stopped down their exposure to make all the lines go away. Not good. You want to have a good balance between the zebra lines and darkest spots in your picture. Overall a good black and white viewfinder can be the best thing for focus and exposure. Normally I’ll use my viewfinder first and set my exposure and then check the LCD just to see if it looks good. Sometimes people will turn the exposure on an auto function to just see what the camera thinks is right and then back to manual to set it themselves. Overall it depends on what you think looks right and what you will be doing with the footage in post.
hope this helps
Chadwik