a) Don't know.  Anyone else?

b) I think you need the v6.5 Upgrade Portal here:
http://seer.entsupport.symantec.com/docs/290185.htm

c) Is just a list of what the master believes are the software versions of clients.  It doesn't actaulyl contain any software.  The next time NetBackup talks to a client, it'll update the list.  I suspect that one is asked to delete it because it causes issues with upgrades - but I can't confirm.

d) You can't - ordinarily.
"bpconfig -tries 0" has been deprecated in v6.5 - there is no equivalent.
You have three options:
d1) De-activate all policies beforehand.
d2) Write a script to manually massage the text file"/usr/openv/netbackup/db/config/sync" to change "TRIES_PER_PERIOD n" to "TRIES_PER_PERIOD 0" and then also update the MD5 checksum at the end of the file - BTW, I don't know how to regenerate the MD5 checksum.  Does anyone?
d3) Keep issuing "nbpemreq -suspend_scheduling" repeatedly and quickly as NetBackup starts, and hope you get your command in before nbpem begins queueing off jobs.

while you are performing maintenance:

nbpemreq -suspend_scheduling

Make sure you dont forget to execute the following command when you are done:

nbpemrequ -resume_scheduling

What version are you upgrading from?  As nbpemreq will not work for any version prior to 6.0.

The following would prevent jobs from kicking off on 5.1 and below:

/usr/openv/netbackup/bin/admincmd/bpconfig -mj 0

sdw posted a link to the upgrade portal - you will find a detailed upgrade guide there that will answer all your questions...
It has information about vault changes, nbpushdata, how to prevent jobs from kicking and LOTS more....

Depending on your current version, this will determine the steps you need to upgrade. As already stated, the Upgrade Portal should provide you with the info you need.

a::  I see in the main doc [290141] where it tells you that it needs to be done...  It does have a link to technote ::---> 280696..
I guess I need to select "OK"....

b::  I see the light....  this command needs to be run on each server....  In the proper order of course...  Yet when keeping a server
at 5.1 ...  the command needs to be run elsewhere...

c::  I'll just delete the files....  Well....  I'll make a backup first before doing so  :)

d::  I'll write a for loop to identify the active policies,  Then send that data to a for loop to deactive them...  And have a for loop that will reactivate
the policies after the upgrade is done

Thanks.....

Joe Despres

No need to disable policies. Two ways of stopping all backups:

Extract from page 15 of upgrade guide:
Suspend NetBackup resource allocations. You must perform this step before you run nbpushdata.
■On UNIX systems, enter:
/usr/openv/netbackup/bin/admincmd/nbrbutil -suspend
■On Windows systems, enter:
<install_path>\netbackup\bin\admincmd\nbrbutil -suspend

Another way:
Stop nbpem: nbpemreq -suspend_scheduling
(seer.entsupport.symantec.com/docs/278938.htm)