I suppose it's possible but I wouldn't say that's quite what I meant, to me the significance of the burning bush story was the fact that the bush was burning but not consumed and what that symbolizes whereas I assume if you were to smoke acacia seeds they would be consumed.
I was thinking more along the lines of how religions began. For example, in an ancient hunter gatherer group you might have a medicine man or shaman who is responsible for the spiritual well-being of the group, often times making use of various plants for healing and communing with the spirit world. In fact, most of the natural psychedelics have long histories of such uses and were generally used in some sort of ritualized setting within the societies that used them. Naturally, insights and information gained during these experiences would influence the thinking of the participants thus impacting their world views and whatever sort of cosmology or religious understanding they would ultimately pass down.
As for where did all the "authoritarian "do as i say or die" shit" come from do you really need to ask? Most obvious would be the desire to control other people. The bigger a religion gets and the further away it gets from its original founder(s) the more it becomes useful as a political tool. Even on a very small scale there is no shortage of cult leaders that desire to gather followers around them and then exert control over them.
Then of course there's also a sincere desire to warn other people that doing some things might be a bad idea and lead one to their death. For example on here we have a lot of people warning others not to start shooting heroin. Is that because they are authoritarian or is it because they noticed through their own experience that going down that path often leads to destruction and death? Of course in religion, there is a lot more superstition mixed in but generally speaking I think one could argue a lot of the things religions warn against actually are based on observations people made over time about what sorts of actions lead to problems down the line. For example, Buddhists might warn us not to use opiates because they lead to sluggishness of mind and insatiable craving. Can anyone here argue that's not at least somewhat true? Similarly with things like sex before marriage, it might seem completely innocent at first but over the long haul one might find that if they spend their youth having sex with lots of people then as they get older they find it more difficult to pair bond and the temporary thrill they got from sleeping around wasn't as full-filling as they thought it would be. Observations like this can get encoded into religions. Historically, religion and culture were often much more intertwined than they are today.
Isn't religion's origin more likely to be in the primal fear of death? When primitive man saw his family drop dead - isn't that the push to start creating fantasies about where they've gone? That's why you find trinkets in Homo Erectus graves - they didn't want to think death was the end. I think that's why all societies have some kind of religion - even the ones that don't have access to psychedelic plants.
I can see psychedelics might affect some people in a religious way but even today the number of people who are interested in taking psychedelics is vanishingly small. Even when we know they are harmless. I remember reading about Maria Sabina - she was the only gay in the village...sorry..the only woman in the village who took mushrooms and she was basically shunned as a wierdo and a freak by the rest of the village. She wasn't some popular person at all - a few people went to her for medical help or to see if she could predict the future for them but they wern't sat round in a group hug.