Questions About Chapter 6 of The Crying of Lot 49

After reading Chapter 6 of Pynchon’s The Crying of Lot 49, discuss the following:

In the final chapter, Oedipa learns about the detailed history of the Tristero. Does this understanding help to bring the mystery and her search closer to a conclusion? Is it satisfying for Oedipa to learn all of this? Why/Why not?
As more obstacles arise (the burning down of the bookstore, Dribblet’s suicide, etc.), Oedipa begins to give up on her quest. Mike Fallopian suggests to her that this might all be a joke orchestrated by Pierce. What is the likelihood that Fallopian is right? If it were a joke, what would this mean for Oedipa?
Why does the novel end as it does? What does this ending suggest about a possible theme or how we might (or might not) find meaning in the novel?