Is it a bad backup strategy in Oracle to have only Level 0 backups and Archive Logs in between with no incremental?
Do you have enterprise edition or standard edition? If you have enterprise edition you can create a block change file and do a true level 1 incremental backup. Doing a level 0 backup is a FULL backup. There is not reason for you to do a FULL backup every 6 hours. Most people do a FULL backup every day and possibly send the archive logs to more than one server. I do two level 0 backups per week and level 1 backups on the days when I am not doing a level 0 backup. If you are new to Oracle you may want to do a backup/recovery class. You should practice backup and recovery on development databases.