Not really possible these days... but I’ll answer your questions;
OzRunways has PNG
Clear customs at Daru
Horn Island leaving Australia arriving Daru PNG
100s mostly all unsealed bush stripes more village then touristy
Im a 2nd amendment believer
Don’t do it.
One of your main problems is fuel. Avgas is hard to find and the whole thing is a logistical nightmare.
Private flying doesn’t really excitement in PNG.