The MAF in PNG is what I know about. Not from personal experience mind you.
Yes, you must be a religious person. You'll need to be able to prove it. if my memory serves me correctly you'll need some formal bible studies training too.
Don't know
Don't know
Yes, the aircraft are well maintained.
Personal safety is an issue in PNG. Expect to know how to use hand guns and many guys (not in the MAF) live in compounds and or have armed guards.