Hey,
I want to suggest a feature.
I'd find UDP Protocol for your multiplayer quite handy.
After flash player 10 UDP connections should be possible.
Some flash multiplayer servers made that already. for example the es5 servers at http://www.electrotank.com/es5.html.
And there is even an opensource project availalbe that supports UDP https://github.com/OpenRTMFP/Cumulus.
thank you for reading,
Manuel Otto