Eric,
 
 BackupExec does drive ADSM as a virtual autoloader.  However, I do not
think you require a license of the Autoloader Module.  I have never
installed this module and all of our backups work fine.  

I believe that the Accelerator Agent is only used when you are backing up
NT machines via another NT machine that is running Backup Exec Enterprise
version.  We do not use this config here, but rather have each of the
Exchange machines running Backup Exec Single Server.  

Dan T.