Perhaps

Hint: Break down subject into two categories:

1. PRB (some refs in links on page 1) and agency's civil remedies per Snepp case. Google - lots of open source stuff.

2. Fed Criminal Statutes re: classified data - case of alleged Israeli spies in DC is recent. You will find that area something of a quagmire - where outright espionage is not involved. Same Google idea.

I imagine that applies to former Agency members as well, but I'm not completely sure.
Answer is in links - along with known exceptions. Sources and methods can be deadly to some of our own people or their agents, even if the data is 30-40 years old. X > Y > Z.

At the very least all profits Ishmael makes from the book will be seized and he'll potentially be facing jail time as well.
Not necessarily; agency GC may elect not to go civil - DoJ may decide not to prosecute. What's the criteria ?

What I'm also not sure about Mike, are the penalties the same for writing about classified things in a book as they are for stealing a classified document and distributing it?
You tell me.