The network ip address and sending port are included so that you can if you want distinguish between different IP addresses, or more than one source from the same ip address using different ports to send. Usually this is not the case, and it is better to sync using x = sync "/osc*/PADX"
the * is a wild card which will match any ip addresses and sending port sending a message to /PADX
Including this information is a feature of Sonic Pi.
You can do a great deal with OSC messages. I have used them a lot in many projects, and particularly in conjunction with the TouchOSC interface, and also with python osc servers to interact with hardware running on Raspberry Pi.
An advanced project I did with TouchOSC was an alarm clock which is entirely driven by osc messages between the interface and Sonic Pi.