I would NOT recommend deleting the DataStore pool (created by default on a NetBackup installation).
It is an available pool for applications which have been written to hook-into NetBackup for application-specific backups via XBSA. XBSA is an Open Group Technical Standard defining a Backup Services API. The XBSA specification defines how client applications can use a backup service, such as NetBackup, to store and manage data. You can even find XBSA usage in IBM Informix OnBar-based backup support.
Reference: Veritas NetBackup (tm) 6.5 DataStore SDK Programmer's Guide for XBSA
http://seer.entsupport.symantec.com/docs/290236.htmHowever, the DataStore pool is Y.A.P. (yet another pool) and I am sure you could use it for other purposes, but to be safe (ie. avoid future upgrade complexities) only use the DataStore pool if an application explicitly requires it.
paul