Quote 7
"I knew my only chance was to make [Old Nick] give me the code. So I pressed the knife against his throat, like this." (2.770)
We doubt Ma is normally a violent person, but being trapped will make a person go to extremes. Ma would probably kill Old Nick, given the chance, if it meant that she could get out of Room for good.
Quote 8
"Not just children," says Ma. "People are locked up in all sorts of ways." (4.1319)
Ma is irritated about having to talk about her captivity on TV, because she knows that others have been through it and are going through it all the time. She isn't special. She's talking about both literal captivity—whether it's other girls like her, or the slaves of the past—and the figurative captivity that comes from, say, being in an abusive relationship. Everyone wants to break free of something, and that is why so many people identify with Ma and Jack and their plight.
Quote 9
"[The air]'s fresher. In the summer, it smells of cut grass, because we're in his backyard. Sometimes I get a glimpse of shrubs and hedges." (2.668)
Ma is starting to describe the Outside that lies directly on the other side of Door. These are a lot of details for Jack to absorb at once, though. He likes the smell, but trying to visualize it all is too much. It's going to take him a while to work up the ability to explore it all.