https://archive.org/details/doom-manual/page/n1/mode/1up
"The story so far" can be found here.
It isn't much, but it is something.
I will explain the hanging people and the dog stuck to the pole.
In the original game, all the hanging people were corpses or at least very close to dying. The Modder changed them to be alive because this mod isn't about death and ruin like the original DOOM. (I assume that is why.) I mean, none of the enemies "die" when you defeat them, and the code for the bodies on the ground (the ones that look like Daisy) refers to them as sleeping. A corpse wouldn't go with the vibe.
I'm sorry, but the HypnoDog tied up also used to be a zombified marine that was either dead or eerily spasming on the pole. And in both cases, they are impaled by the pole.
( I made this post 3 days ago but the original seems to have gotten stuck in limbo. Lol. )