Official Best Practise
http://support.veritas.com/docs/340834
Try to keep only one grt backed up server per job. ( exchange in one job for example)
Only 1 source side dedupe server per job
The GRT or "Source Side Dedupe" Resource should be the first in the selection list.
Yes you can add the duplication templates to your policys. They should run in squence.
I tried it with schedule, which resulted in 1 job fails, because he didnt got a tape.
No only 1 Job per Tape. mulitplexing is a enterprise feature ( netbackup) i think.
Hint: when you have a issue, reboot and retry.
The dedupe store also seems be sensitive to broken grt backups.
But this can be fixed with a restart of the purdisk services.
Regards