dovecot - Sep 2013 - adding user for maildir and mail_location

Dear all,

I install
postfix ,postfix-mysql,dovecot-core,dovecot-mysql,dovecot-pop3,dovecot-imapd and
postfixadmin form debian repo.
Also i configured postfixadmin.
It work fine with mbox storage, But i need to change it to my
path/domain/users
i saw devecot have mail_location directive.
i changed it to :
mail_location = maildir:/var/pool/%d/%u
My questions are: 
1. how can i assign mail_location directive to a maildir storage
according to my path and domain/user , such as qmail?

2. i want to mysql, i need to write bash script to add/delete/update for
doing them ? or dovecot provides them with command line?

3. What's permission of path in mail_location ?

4. How can i enable mysql in dovecot?

My dovceconf -n is:
//////////////////////////////////////
# 2.1.7: /etc/dovecot/dovecot.conf
# OS: Linux 3.2.0-4-amd64 x86_64 Debian 7.1 ext4
mail_location = maildir:/var/pool/Maildir/%d/%u
namespace inbox {
  inbox = yes
  location = 
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix = 
}
passdb {
  driver = pam
}
protocols = " imap pop3"
ssl_cert = </etc/dovecot/dovecot.pem
ssl_key = </etc/dovecot/private/dovecot.pem
userdb {
  driver = passwd
}
/////////////////////////////////////////////////////

Yours,
Mohsen