1. Boo Radley is a mystery. How did he become this way? Why is he like that? Boo Radley was fascinating and/or frightening because he was different. Boo was the town's weirdo, him and his family, so, never seeing him and hearing exciting stories about what Boo did really got them excited and curious.
2. Scout can already read well beyond her grade level which frustrates Miss. Caroline. She also demonstrates that she can write. Scout then tries to explain why Walter Cunningham can't accept a lunch money loan. Miss. Caroline is just frustrated because she is so out of touch with the kids she is teaching.
3. This tells us that both Calpurnia and Atticus value human decency. Atticus is quick to talk about farms, which Walter can relate to. Calpurnia understands that, even though he is white, Walter gets little to eat at home. She demands respect for Walter as a guest and as a human being. The law "bent" for the Ewells because the town knew if they didn't, his eight children would starve. And they also knew with a father like Bob, they couldn't keep his offspring in school because most of them were as bad as him.
4. At the end of chapter 4 Scout says there were two reasons she wanted to quit playing the "Radley game." One was because Atticus showed up and caught them. Jem doesn't think that Atticus knew what they were doing, but in chapter 5 we find out that Atticus did know. The second thing that Scout mentioned in Chapter 4 was the laughing she heard in the Radley house.
5. Miss. Maudie's comment about "foot washing Baptists" is not an attack on the Baptists, but rather a chastisement to the hypocrites who set themselves above others all while acting in a non-Christian way. Because some one with a Bible on their hand can use the power of it on the wrong direction.
6. They are simply curious of Boo. They heard rumors that he comes out at night to eat animals. They wanted to catch a glimpse of him. It was also a form of boyhood bravery to take a look.
7. Boo was watching them. When Jem goes back to get his pants at the Radley house he finds them mended. He expected to find the pants where...