I don’t think it is safe to have a user with root privileges.
In many instances like system updates, OMV LX 3.0 demands user password instead of the root one.
I have seen this in OMV 2014.2 and there has been a problem to configure user privileges that was solved only later.
I have tried to change the defaults for passwords for system update, hardware configuration, etc at
MCC => security => Configure authentication for openmandriva tools, but changes did not take place; so I think OMV LX 3.0 has the same problem as OMV 2014.
Did somebody else also experienced this?