I've been playing since the end of world 2, and i have never once been killed or even attacked by another player. Probably a combination of good luck, humility, and a comically-bad-but-just-good-enough knowledge of languages. I have met many other hearthlings in my travels (most of them far, far stronger than me), and have never been attacked just for saying "Hi". Hearing other people's experiences, I consider myself lucky, since apparently some of you crazy bastards just kill on sight. But i'd say that some good suggestions for remaining alive when visiting your neighbors are: 1) Don't wear anything threatening/expensive, 2) Don't be moving around and active while talking, 3) Don't venture any further into their territory/village than you have to in order to make contact.
So the most fail-safe way to stay alive in the hearthlands? Be nice, but more importantly, be lucky

And as far as boars and bears go? Fukkit, you're on your own

"Bein' a minotaur is a lot like bein' a regular human except moo" - J. Rowland