Regarding the dry erase board in the bunker, there was a very in-depth analysis of it’s contents on the Dayz subreddit explaining the chemical equation, sadly I can’t find it now to link to it. If I remember correctly it’s essentially phosgene + something else, with the smudges making it less of an anarchist’s cookbook lol.
"The drawing depicts the substitution of a chlorine atom (Cl) with a hydroxyl group (OH) through the addition-elimination reaction. Under basic conditions, the OH then loses an H+. Subsequently, O- attacks ClCH2CO2H and ejects the Cl. The result is that CH2CO2H is attached to the benzene ring through an ether linkage" to which someone says that this will go onto make "2,4,5-Trichlorophenoxyacetic acid". It seems they were checking purity of this acid that is found in agent orange.
There’s a sword & a cross with a medieval helmet where the gas station is on the road that heads straight to the bunker behind the gas station where to cabin is on the right there is a few trees and a seating area behind it in the trees is where its at i just found it thought someone would know the backstory to it