Hi. I'm from Buka, Bougainville. But I live in Port Moresby currently. I have lived most of my life in Buka.
I would gurranty you that it is pretty safe and relaxed environment. People won't mind your business unless you have something against them. And just like any other country, you are safe when u are in the right place and the right time.
Understanding the culture and respecting the culture is good thing to do, then you would feel part of the people.
