The nvram for logging on EXOS switches is small, and is not what you see in show log, nvram is what you see in show log messages nvram and these are the ones that remain after a reboot.ideally you should have a centralized syslog server like for exam...
You could tail /usr/local/Extreme_Networks/NetSight/appdata/logs/server.log, when you see something like WildFly Full 10.1.0.Final (WildFly Core 2.2.0.Final) started the server is ready.
Yes, that should be possible. You can do an NBI query like below.{ network { device(ip: "<IP ADDRESS>") { id, ip, entityData{ port(ifIndex:<port ifindex) { ifIndex, ifName, ifDesc, } } } }}