Thought-provoking discussion. I agree that psychedelics bring with them serious risks, and I think these are often downplayed in the community. Nevertheless, they can also catalyze healing. One of the ways in which they do so is exactly related to this idea that we should be suspicious of attempting to rid ourselves of the shadow parts of our selves. Indeed, for me at least, psychedelics often reveal hints of the shadow that are otherwise entirely unconscious, while simultaneously allowing me to be ok with these bits and accept them as true and valid parts of myself: even if I wish they weren't.
One way to think about this unconscious shadow (not Jung's) is to imagine it as the summation of the coping mechanisms that we developed as infants. Once upon a time this was the best we were able to come up with in order to deal with the onslaught of feelings that were too intense to bear, and that we had no hope of understanding at the time. Now we walk around the world reacting to stimuli in a manner that was developed for reasons obsolete and forgotten. We use our current logic to give illusory reasons to our behavior. For example, I think "I got angry at her because she was being rude!" when, in reality the truth is more like, "I got angry at her because our interaction conjured this feeling in me that I couldn't bear to feel as an infant! I spent my entire childhood and then adulthood structuring my life and relations to continue avoiding feeling that feeling! And how I'm feeling it! Agh!" We put the blame on "the other" for what we can't bare to own in ourselves.
We are fragile and ready to snap, and this shadow is indeed dangerous, but only in as much as it is pushed away, avoided, and let grow in shadow form. What if, instead, we were able to be mindful in those moments where we felt those unwanted feelings, and we were able to change gears: What if at, "I got angry----!!" we could stop for a moment, and feel everything our body is feeling--feel it completely and without commentary or retrospective explanation--instead of avoiding it (for our reaction, including the anger and everything that follows, is exactly our way of not feeling these feelings). What if we could see clearly that, even if we wish these feelings weren't there, they are not harmful in and of themselves. They can be accepted, maybe even embraced as true and valid feelings that are part of who we are and only incidentally catalyzed by the person next to us. They have much more to do with us than to anything "happening to us." What if we knew that these unwanted feelings were synonymous with freedom: That if we could welcome these feelings instead of reacting with our expired coping mechanisms, we would taste enlightenment itself, the taste so different from what we expected and hoped for, but alive with energy unlimited.
Even more than making the unconscious conscious, this is one of the things that psychedelics allow for practicing. It's the reason for the typical trip advice: if something disturbs you, welcome it instead of pushing it away. Still I agree that there is a great danger here: Psychedelics can have a profound impact, but if the practice is not continued without them, then they may indeed make things much worse. Better and safer to have stuck with your infantile coping mechanisms that have brought you this far. Psychedelics may start you on a path, but they will not bring you to the goal. Will you follow that path now that you've started on it? How far will you go? Now that you know, what choice do you have?