Thank you for the insights. The suggested options seem to be authority and brute force, and it seems that I cannot do either one very well. Maybe it's because I still think dream people are real on some level, especially if they resemble some real friends for example.

I'm really unwilling to use brute force on anyone except video game monsters, or characters who behave aggressively. I'm not sure what would actually happen if I started to bash innocent dream people - probably I'd just wake up feeling very guilty.

Authority then... well I got to the "mother of the girl" scene again, this time her telling me that I should not disturb her daughter since she is studying very hard. This is even worse since it directly appeals to my reasoning, and even if I told the disturbing character to stay out, I would still keep the guilty feeling.

Any hints on how to proceed? Should I just visualize the outcome more carefully before I open a door or make a telephone call? How did you actually gain control/authority over your dream characters on the first place?

This webcomic actually describes my feelings quite well: Wayward Sons: Legends - Sci-Fi Full Page Webcomic - Updates Daily