it's one of the most epic myths that caught my attention and i spend much time wondering and trying to understand.
first you must to know that those stories wasn't literal and it was symbolism and coding for higher spiritual knowledges!
My Vision for the topics you mentioned is this way:
the snake is a symbol for ouroboros, the everlasting serpent eating its own tail or it representing the kundalini. both are containing and devouring powers beyond imagination.
and it only steal the plant when he went to enjoy him self and fell asleep! the sleeps allegory here can be representing something about the state of conscious or being oblivious!