MPX Node transports composite FM signals, not Left/ Right audio. It does not contain Livewire.
Once you assign an IP address, you can use any modern browser (PCs, tablets, smartphones) to access MPX Node's HTML-5 based GUI. Control pages let you set GPIOs, update firmware, view levels, check health, set IP and port addresses, etc.
MPX Node supports both, and you can set IP addresses directly from the front panel.
Yes, MPX Nodes come standard with a rack mount kit. Mounting options are the same as Axia Xnodes since the chassis is the same. One unit can be be mounted in a single rack space, or two can be mounted side by side.