Hi,
Here's some answers:
1) An easy way to find out the barcode rules is under Media and Device Management, find your robot(s), right click each robot, Inventory robot, Advanced Options, and one of the tabs is barcode rules.
2) De-activate all media servers is done through Netbackup 6.0, it's not an option in Netbackup 5.0. You carry out this step once you have upgraded the software to NBU 6.0, assuming you're going to 6.0.
I used these documents for my upgrade:
* Technote 285590 Revision D
* Netbackup 6.0 Installation Guide
* Opened a call with Symantec ref NBCC
* Performed a test upgrade first with a copy of my live environment
It was less painful than I thought.
Good luck.