Short answer to risk: yes. Not secure. That privilege means your power user reads the entire command line for ANY process, sometimes privileged processes get started something like this:...
Yep, only current shell session will use those variables.
But be advised, oracle software will require some /tmp space to function properly.
Some being written in software documentation, being...
A little research reveals that Oracle (Sun) partner with COMSTAR for the iSCSI connectivity and this page from 2013 says that (at that time) scsi3 PGR was not supported.
So you just have to mirror current disk. First remove old boot environment (ludelete), then follow those instructions: Example?Creating a Mirror From root (/) (Solaris Volume Manager Administration...
Yes, it is possible. Just create zpool on which you want your zones to reside (for example "zones") and then specify zonepath property for your zones to be under "/zones/".
Specifying /dev/null tells the kernel that you have an empty /etc/system and it boots using all the default kernel parameters. Once you are up and running you still need to fix the /etc/system file.