When Buddhism began, 99%of the population were illiterate and very superstitious. Taking this into consideration, teachers at the time would use expedient means to get the message across. If this involved telling the audience, that they conversed with Devas' or so on, It wasn't meant to be literal.
The best commentary I've read was by, the Korean Mu soeng. However here is part of my take. Form = Existence. Void/Emptiness =non existence. So a basic formula is, We exist, we don't exist. We neither exist or don't exist. We both exist and don't exist. Everything comes from emptiness...
Then end results of Taoism are completely different to Buddhism. So except for some similarities in the lower echelons of practice, they are different.
It's only attainment if one thinks about it. This is also another way of saying everything comes from the mind. If you don't think about it, what is attained?
There is a difference from what one believes makes one happy, to what actually makes one happy?
Of course there is the old adage, everything in moderation. Happiness, people generally forget that this is the main aim of Buddhism. Let's not get confused however, with "highs", more a constant...