The instances you stated in your question are just stories passed down through thousands of years. I'm sure the word serpent is just a synonym for something else.
Is judaism and Christianity a serpent cult? Moses turns a snake into brass in the desert and heals people and Jesus compares to a snake on a pole. Hermes carried a snake on a pole, Mercury teo snakes on a pol, and Buddha had a serpent above him.
Serpents and Snakes have been symbolic in many religions.
https://en.wikipedia.org/wiki/Serpent_(symbolism)
The definition of "Cult" fits all religions if one regards its initial meaning:
Thinking of either Judaism or Christianity as a "serpent cult" is not going to help you understand either Judaism, Christianity, or the phrase "serpent cult."
"Serpent cult" is a phrase with a more specific meaning that is not apparent by simply looking up the definition of "cult" and adding "serpent" to that word to create that phrase.
http://www.ancient-origins.net/myths-legends/tracing-origins-serpent-cult-002393
