I'm a little (little?) late to share a thought about this since I just came upon this site but, I believe astral projection can be dangerous. I don't know about your experiences and I always read good thing about it, which praises it saying that it's a beautiful experience. From my experiences, I think even if sometimes it is enjoyable, there is always a chance of meeting other entities which our physical eyes can't see. I really don't want to call them 'supernatural' since I believe what happens happens within the nature so they are just as natural as we are.
I don't know if these entities can really hurt you physically, and since when you're on an astral plane and you get scared, your physical body pulls your astral body back immediately; I don't think they can really hurt your astral body or your silver cord. What they can do is, follow you back to your physical body.
