If I were needing to interview a midwife I would ask straight out how she feels about being completely uninvolved in the labor process. I know a lot of midwives just have to get in there and do things even when the mother and baby are fine, and that's not for me.
I would ask also how she typically manages labor, in detail, and if she wasn't being free with the detail, I would ask her more specific questions about every aspect of labor, for example, Do you feel that the mother should breathe a certain way? Do you feel that the mother should adopt certain positions or a certain level of activity? How do you monitor the baby's heartrate, and how often? What does a normal pushing phase look like to you, when do you know it's time to begin, and what is your role in it? How do you feel women should deal with pain? How do you feel about the necessity of cervical checks? How do you feel about active management of third stage? Etc.
Then, about what she would do in the event of various complications, and what her transfer protocol is (when she is legally required to transfer.)
And the medical stuff, does she carry pitocin, oxygen, etc.