Can someone explain Pirates of the Caribbean: At World's End to me?

Just say At World's end a minute ago. Yes, a bit late I know. I get
the general plot line, but a lot of the small specifics I find
confusing. Example:

Can someone explain the deals between Will, Jack, Feng, and Brackette?
There were like 6 different deals revealed in 20 minutes. I understand
that Will wants his father freed and Jones dead, and Jack wants to
stab his heart. But what about the transactions with Brackette and
Feng?

Second of all, how did they save Jack from the Locker, and not
Elizabeth's father? And how did Clypso resurrect Babossa but not
anyone else?

Clypso didn't know that Jones betrayed her? That scene where Will
tells her that fact confused me.