^Good for you as you were able to adjust well here in PNG in your 4 mos stay however I would not say that this is not a dangerous place compared to the places you mentioned in your post. And good for you as you were not able to experience the dangers of this place yet
We have been here for 4-5 years now. I have experienced and heard a lot of not so good things here in POM not only for the Expats but for locals as well. The good thing is that we have seen a lot of changes especially in terms of security, maybe because a lot of people are now vigilant in terms of their security.
One thing is for sure, always take precautions when going out especially at night. Be vigilant and be mindful of your surroundings. You don't want to go to places with a lot of locals especially by yourself or if you do not have security eg. local markets etc. Some of the people I know died or got hurt because they thought PNG is a "SAFE" place. Mind you, even locals do not dare to be out at night, so just a piece of advise, do not be complacent especially when it comes to security.