How to backup and remove solaris zones?
It depends on what kind of filesystem your zonepath is, if you are using zfs it could be just a matter of taking a snapshot and using zfs send to a file. Otherwise some methods are listed here http://www.solarisinternals.com/wiki/index.php/Zones_Best_Practices#Zone_Backups
I'd advise to backup any network drive (nfs share?) with a separate process ,using maybe a tar or cpio.
This is a good procedure to delete a zone http://www.logiqwest.com/dataCenter/Demos/RunBooks/Zones/deleteZone.html