Hi Mickelin, Welcome aboard. It's nice to have some fresh blood.
You can already target multiple eventghosts simultaneously (since we use a broadcast by default) as long as they are all set to listen to the same port, and you can send individual commands using a different prefix in the event like this:
A.Volume.Up (to the turn volume up on system A)
B.Volume.Up (to turn the volume up on system B)
I'm happy to extend the command-set for eventGhost if you want to be able to target different ports, or IPs. Just let me know what would help you the most. The more details you can provide, the more likely that you'll get exactly what you want, though of course I always try to keep the "big picture" in mind, and make commands as flexible as possible for all users.
I can do something similar for MediaPortal. In this case I could make commands to change the default IP to send commands to. The simplest would be if all your MP machines used the same username and password so we only need to change the IP, but it is also possible to have a command that will change the ip/port/username and password. Should not be too hard. Again, just let me know what you have in mind.
For the record Mobiola is better than (edit: pocket audio). Less delay, and more stable. Still not perfect though.
I think your biggest challenge is going to be setting up multiple microphone inputs to VC.