Quote 7
In Room I was safe and Outside is the scary. (4.1004)
A home is a place you feel safe. It takes a long time for Jack to find a safe place when he's in the Outside. No wonder he wants to go back to Room even though other people, including Ma, see it as a prison.
Quote 8
I'm in the house with the hammock. (5.1)
Note that Jack calls Grandma's home "the house" at first. He doesn't call it home because he doesn't yet feel comfortable there.
Quote 9
How is it home if I've never been here? (5.808)
This is a good question. Ma calls her new apartment "home" mostly out of a hope that it will be. Jack understands, at five, that they will have to make it a home; it doesn't come ready-made that way.