Is yum-cron auto-update mechanism safe for production systems?

Everyone understands what risks exist with a "normal" package's updates on production systems. Update may change the functional of application, data format, compatibility with other applications, e.g which may result in business-application failure.

1)Is yum-cron with "update_cmd = minimal-security-severity:Important" safe for production enviroment use?
2)What type of changes can update with this severity do to application?
3)Does this security fixes change package version?
4)Does RH responsible for possible problems that this mechanism can cause?

Perhaps there is documentation which provides answers to my questions?