Well I had just typed up a detailed reply to the post and then somehow lost it, I apologize if it ends up with a double post. In a nutshell....
The docs are not shipped until after the package is paid in full. The docs are tied to your confirmation number so if you were to cancel then the "vouchers" would be canceled in the reservation system. No one can cancel a package and then still use the vouchers for a free stay. You do incur a fee if you cancel within 45 days of your arrival date and you would incur a change fee and a new doc fee if you made package changes in that 45 day window. Disney would then ship you a whole new package with more luggage tags and coupons. If you make a ressie about 10 days prior to arrival date then you receive the docs via UPS, if you make a ressie about 5 days prior to arrival date then they are held at the front desk for your check-in. You dont have to have the docs to check in, just give your confirmation number.
If using a TA, they would receive the docs after posting final payment for the client and receive them on the same schedule as a direct booking guest woud receive them. The TA then delivers/mails/expresses the docs to the guest.
The luggage tags (in the 2007 packages) come in handy, we have about 50 of them!! Have a great trip!