I guess I need to address your main question first
Symantec do not recommend flat file backups (or copies) of BKF files and in some cases your ability to restore will be extremely time consuming and perhaps even fail if you do flat file backups. As such we only recommend duplicating Backup to Disk content with duplicate jobs inside of Backup Exec.
To explain the reason, think of the Backup Exec Database (BEDB held in SQL), the Catalog files (in the Catalogs folder on the media Server) and the content of the B2D location (BKF files and IMG folders) as "one big relational database". If you let any part of the big database become inconsistent from any other part then there will be problems.
Now imagine this scenario - you use a load of B2D files back in April (so beyond 4 weeks ago) and these are copied using your Leased line/NAS function to somewhere else, then after 4 weeks later jobs overwrite the B2D files in question and re-write the catalogs and the database content for the media index accordingly. (In fact from April this process would happen a few times.)
Then today you decide you need to restore the old structure to restore something ...
- What do you do with the 'new' versions of the same files that hold valid more recent backups?
- How do you get the BEDB content back to consistent with the files you have just copied back.
- How do you update the catalogs?
Basically to be consistent you would at least have to restore the bedb from the same date as you copied the B2D data and be prepared to run another catalog job - but this still leaves you with the problem of how you handle your more recent data - which would mean shutting down the backup servers and copying away catalogs and the current database before you copy the data back to the NAS and start the actual restore.
The other option is only restore that data to a clean media server that has never run any jobs and then just Inventory and Catalog what you have restored - obviously this needs you to have a clean media server available to do the restore.
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Against you other questions:
IMG folders are part of the GRT process - and are equivalent to BKF files for backup sets using GRT (Exchange, Active Directory AVVI etc) hence their content is critical as if you don't protect it, you won't be able to restore.
BESR is currently a seperate product with no integration with BEWS. However I suspect (but you might want to post in the BESR forums) that you can copy your BESR images aorund more easiliy than the BKF/IMG information. As far as I know it won't cause problems with Backup Exec on the same system - with the possible exception of what happens at a VSS level if you run a Backup Exec job at the same time as a BESR image is being built.
CPS provides added functaionality to Backup Exec in terms of a replication environment for data that can then be backed up - I think it is now bundled as part of The Media Server and Remote Agent licensing, however is not installed/enabled by default - there should be more information in the admin guide about it's use and how adding CPS into Exchange changes your backup process.
