| Quote #1
James doesn't want to look rich, but he certainly doesn't want to look poor. While he laughs at Edmund's joke at Harker's expense, he's upset that Harker might think him low-class for having an impoverished, rude tenant. James also doesn't want to hear Edmund's Socialist rhetoric. In other words, while he resents Harker's airs, James doesn't want to be a part of any revolution that would hurt the rich folk.
| Quote #2
Here we can see that the Tyrones aren't the richest people in the neighborhood (they don't have a Mercedes like the Chatfields), and we begin to see the consequences of their social class limbo. Basically, since they're not poor, they don't associate with the lower class, and since James doesn't want to seem like a rich fat cat, they don't associate with the rich people in town. Thus, the Tyrones don't have a class to fit into, and it's part of the reason why Mary's so lonely. What's more, Mary herself seems conflicted about whether or not she wants to be a part of the rich summer folk social group.
| Quote #3
Again, Mary shows some resentment that James has made them look like poor people to the rest of the town. The "home" sentence is particularly important, because we're reminded that Mary hasn't had a place to call home since she was a child.