The part above is a similar experience I had. In the sense of feeling like messing with things in a dream was wrong, because I was actually messing with people.
What I can point out is I have met others in the dreamscape that seemed to be just as sentient and aware they were dreaming as I am. One was far more advanced than I am and she told me somethings about reality that I felt so true to my being, but could not fully remember once I woke up.
The full kicker was me seeking out my wife in a lucid dream and finding her waiting in a line in a dream about her High School years. I whispered to her, "Do you know that you are dreaming?" She looked at me with an upset expression, like I was intruding in her dreamscape. That was also another time when beings who seemed to be some sort of enforcers arrived and I have to admit I ran. We moved through dream locations, at speeds that made everything a blur. Once I got ahead of them enough to concentrate, I woke myself up.
Now, the interesting part about that experience was I asked my wife about it the next day. Since she fell asleep in our loft watching a movie and I fell asleep in our bedroom, I felt there was no chance of me speaking in my sleep and her hearing it. She looked with shock at the question, and then told me exactly what I said to her. Not only that, she remembered being upset that I was intruding into her dream. She is not the only person I have done this too, but she was the last one. I came to the conclusion that intruding on the dreams of others without their permission is an invasion of privacy, and maybe against some collective understanding we has humans have with each other.
Now, how do I explain it all is seems to be the collective unconscious we all share as Human beings. Our consciousness may just be the tip of a wave on top of a vast sea of unconsciousness that is actually shared among us all, according the the theory of Carl Jung. So being able to move into other dreams, which are in that vast unconsciousness may also allow us to move into each others dreamscapes. A theory, and so can not be proven by me or anyone else, but like I said before, I have checked in my waking life to confirm things and surprising results have been found. I Just have not found enough conclusive evidence that would allow me to outright state it is all true.