Go Set a Watchman - Some questions (SPOILER ALERT)

[Nitzan]

Hi,
There were some parts of Go Set a Watchman that I did not understand. I'd appreciate your help.

1. At the end of chapter 2, while talking to Atticus about what the New York newspapers have been saying about the south, Scout replies:
"I haven't paid any attention to [the newspapers] except for the bus strikes and that Mississippi business. The state's not getting a conviction in that case was our worst blunder since Pickett's Charge." What is she referring to?

2. At the end of chapter 10 there is this paragraph:
"Had she been able to think, Jean Louise might have prevented events to come by considering the day's occurrences in terms of a recurring story as old as time: the chapter which concerned her began 200 years ago and was played out in a proud society the bloodiest war and harshest peace could not destroy, returning, to be played out again on private ground in the twilight of a civilization no wars and no peace could save."
What does that mean?

3. At the end of chapter 14, Scout's first talk with Uncle Jack, he tells her:
"What was incidental to the issue in our War Between the States is incidental to the issue in the war we're in now, and is incidental to the issue in your own private war."
What does he mean?

4. At the end of chapter 18, Scout's second talk with Uncle Jack, why does his confession to being in love with Scout's mother shame her? She says:
"I'm so ashamed of myself I don't know what to do... I could kill myself" etc.

5. Again at the end of chapter 18, what does the last line mean? Scout responds to Uncle Jack's quote with another quote: "But we only cut respectable capers." I understand it's from the same song her uncle quoted, but is there a deeper symbolic meaning?

Thanks!