Dear All,
Regarding the "Allow Network" connection prompt, when Isadora starts up, it creates a multicast send/receiver port. This is used to allow the Net Broadcaster actor to send messages without knowing the IP address of the other computers on the network. Perhaps it is the multicast part of the connection that OS X doesn't like.
The multicast address used is 0xE1000001, which 225.0.0.1
Maybe that allows you some clue as to how to get around the prompt. But it could also have to do with the fact that Isadora is not "code signed" -- see this article in Stack Overflow about Java apps.
http://stackoverflow.com/questions/2641254/java-app-on-mac-asking-for-allow-network-connections-everytime
I've been meaning to do the work to code sign Isadora so that Gatekeeper won't throw fits when you to try to install it. But, as always, I'm prioritizing features and the important bugs
I hope that helps in some way,
Mark