Why didn't Arararagi just give her the snake charm? Then she would have become a god. Hachikuji would make a good snake god.
I'd give her my snake
DARRRRRRKNESSSSSSSSSSSSSSSSSSSSSSSSSSSSS IS THE HEARTSSSS TRUE ESSSSENNSSSSSSSSSSE
Because all Hachikuji wants is to hang out and talk with Araragi. She would've been a terrible God, and would've been eaten anyways.
Probably because he didn't have it at the time. That was the first time he met Gaen, she probably gave it to him when he did one of those favors or something. Don't forget Nadeko Medusa takes place in the end of October / beginning of November while Shinobu Time takes place in late August.
Because Nadeko had certain affinities with the snake god in the charm. Doubt that Hachikuji would have become god with the charm
Didn't have the talisman yet. I doubt Mayoi would have wanted it anyway.