re: tape utility to check for writeable tape -
I had the same problem and solved it by writing one file to tape at the
beginning of the job stream.  If that file was not writeable because of
missing tape or write protection, the job waits for tape readiness, but
doesn't lock the rest of the files.  If the tape is in and not protected, the
file is written and the next steps go on to do the "real" backup.  You must
of course put the tape back ready, which in my case was done with a
Roadrunner command.  I believe other utilities allow you to do that if you
aren't using Roadrunner.

 !JOB JRRFULLB,BACKUP.SYS,UTILITY;OUTCLASS=LP;HIPRI;PRI=CS
 !FILE TTT;DEV=18
 !FILE LLL;DEV=14
 !RR.PUB.TYM
           my comment - storing the file jrrfullb to test readiness of drive
 SELECT (JRRFULLB.UTILITY.SYS)
           my comment - autoloading, waiting 120 seconds, autoreplying
 FULL TO *TTT AUTOLOAD 120 AUTOREPLY
 AFTER ERROR QUIT
 /GO
 EXIT
 !WARN @;LOGOFF IMMEDIATELY!  AUTO BACKUP STARTS IN 15 MINUTES!
 !CONTINUE
 !PAUSE 900
 !SHOWJOB
 !CONTINUE
 !WARN @;  AUTO BACKUP IS LOGGING YOU OFF NOW!
 !CONTINUE
 !RUN XLOGOFF.PUB.TYM
 !CONTINUE
 !LIMIT 0,0
 !CONTINUE
 !TELLOP BEGINNING BACKUP
 !RUN RR.PUB.TYM
 SELECT (@[log in to unmask]@ DBSTORE) UNLOCK BY FILE COMPRESS=2
 FULL TO *TTT AUTOLOAD 120 AUTOREPLY
 AFTER ERROR QUIT
 REPORT TO *LLL
 /GO
 EXIT
 !CONTINUE
 !LIMIT 12,90
 !CONTINUE
 !EOJ

Hope this helps Terry - see you at HPworld  -  Allan Chalmers, Thomas
Lighting