Maybe I'll address the most tangential, the Fly Agaric: >>49243
Following Slovborg's personal xp and autistic expertise which he did his research.
Amanita muscaria produces ibutonic acid, which turns slowly into muscarin as sunlight effects the mushroom. Both water soluble and can be soaked out of the "fruit", and do the same process in a bottle. The digestive system/liver of animals (such as humans) also process the raw ibutonic acid to refined muscarin. However this process also has negative effect on the body, similar to hangover. Taking pure muscarin has no such effect, just intoxicates. Neither has real hallucinogenic properties, the effect is closer to being drunk, it is also causes changes in perception (Slovborg said he thought his bed is too small for him or some such). So maybe it causes to see weird stuff, but not like talking to ghosts or whatever. I think there are videos on youtube people eating it and getting drunk.
Fly agaric needs some temperature to grow, not hot, but "Arctic" communities, nah, perhaps on taiga. It's the northern woodland both in Europe and America, so liek the region of the Great Lakes. It can grow further towards north, just the growing season shortens on. Also if it was consumed on Dec 21 it could be only dried mushroom, but drying is one possibility to refine ibutonic acid. And this is important, because when shamans consumed it (they did, this is true) they did to turn the ibutonic acid to muscarin, so they were only one effected by the hangover, and not the rest of the tribe who consumed his piss and got drunk. But if the mushroom is dry, no need for the shaman. Or reindeers.
So all in all I feel the article on ffungi.org falling short.