The most valuable buff (in my point of view) is the first one. Since it helps in grave situation. You dont want to die in this game, do not want at all. Not because of item loss - its all about experience. And first buff from deer boss gives you a chance to survive.

And yes, hanging trophies does not trigger events. You do so when you kill bosses.

P.S. Just dont kill the last boss. He does not drop key item atm (so you ll need to kill him again when new content released) and his death triggers "The Horde is attacking" event.