I would like to start running individual levels, but I have one question. Do I have to start a new game so Quinn is at the door, or can I use a 100% save file to get to levels easier? If it has to be a untouched save with Quinn, that is fine. I just wanted to check. Thank you!

Untouched yeah, just because if you do this as a NG+ then stuff would already be exploded.

Thank You!