I submit this film is the only pure Friday the 13th film of formula, despite its eccentricities, as the overall plot is purely Jason killing without any other supernatural trimmings, save for his being hard to kill, past any other idiosyncrasies of the film's production(ie the movie ranch and the bikers, and the fake deaths)
Shamanism is always waiting to nod towards proof of manhood, but confounded by reality, like the cool trembling hand of a stranger's touch in the dark of the night; it is also forgotten when achieved, taken for granted, like the watched pot of proverb that never boils while the hungry waiting eyes study for any sign.
Here Jason is not the healing arbitrator shaman as he is in some of the other films, but he along with three of his victims are the Trickster of archetype. It is the old trickster who is most notable to me-the pothead, who finds his death by the fusebox after being told to "man up, man". So it is the very will to power and his trial of manhood that destroys him. The mildly cute trickster is murdered upside down while walking on his hands. No other subtext need be mentioned with him. He is not subverted or inverted in theme, nothing aside from settling in to have sex, another rite of manhood foiled by the main trickster from the shadows. The pathetic Trickster Shelly finds himself strung up and in danger several times in the film, but we are not shown the killing stroke, while he survives to die in front of an annoyed woman, and his final joke is then borrowed by Jason: the legendary hockey mask that was to become the murderer's icon.
The farmboy literally says "I'm just a dumb old farmboy", so from this not-so-subtlety I paint with a broader brush and say the film is striving for simplicity and clear typology. The pothead is the older Trickster, who has come to nothing so far in his life. The women are outgrowths of their men, save for the leading lady.
Jason himself is revealed to be the ultimate Trickster, beyond the hockey mask, as an old attempt to murder the leading lady is revealed, Jason being foiled by unknown means, with an impotence of youth. But here he is embarking on a spree, adopting iconography, murdering by the dozen, and making it all look easy, with the righteous motive of revenge fading into the background while he becomes simply a hunter of sorts, maybe even the Trickster of a god that pervades regardless of region, seemingly coming down from the clouds like a thunderbolt, at his own whim, called forth like the heavy hand of nature itself when the time is right and a soul is rip for being tricked, plucked for the gods.