I am comfortable with direct-entry midwives and have used them myself.
With any midwife, I would ask about her education and experience. Education varies and experience can vary widely, whether we're talking about DEMs, CPMs, LMs, or CNMs. Most CNM programs don't require any out of hospital experience. If I'm having a homebirth, I want someone who was trained in out of hospital birth. I also think that we shouldn't be afraid to require more education for CPMs and LMs.
When hiring a midwife, I'd ask:
How many births have you attended? In what settings?
How were you educated?
What emergencies are you trained to handle?
How do you handle emergency transports?