This is something I tried about a year ago, but now I'm seeing that the issue may not be resolved. But it's been a year, surely there must be a way to get Wirecast to work with Red5? As far as I can tell Wirecast is the only Flash Encoder to not work with Red5.
I'm sure you know it already. Red5 has been updated is again being actively developed. Wirecast is working for some time now. The problem was that red5 didn't support AAC audio as far as I recall.