There is no Way you can rename the bkf files by the backup Job .. There was an feature in backup exec 9d and ealier through which you can add media description through the backup Job, but this feture was removed in the later version .
You can put an enhancement request ,an Idea so if more number of pepole vote on your idea , Symantec will try to get this feature back again in the later release.
For setting up a duplicate job on the USb drive , 1st you need to configure your usb drive in backup exec as a removable backup to disk folder . if you want the duplicate job to run at some specific schedule you need to configure the backup job via policy .