Nice job you've done there. Regarding the Streaming software provided by liveatc: it can use only a soundcard at a time. It is not able to create more than one stereo stream. The other guys that stream more than one feed, they just install the liveatc's software as many times as they need: if they have 3 feeds, they install the software 3 times. I know, it is not a professional way to do like this. I think you should speak to Dave. Maybe he has a special version of streaming software capable to use more than one soundcard at a time, or to use a multichannel soundcard and to generate more than one stream at a time.
On my single computers that carry multiple streams (BOS, PHL, JFK, SFO, soon EWR) I use a Delta 1010LT sound card, a card with 8 analog inputs. All those feeds run on Linux, which has ALSA sound card support for the Delta 1010LT sound chip. I launch a single instance of Darkice (feeding software) for each feed and it is all automated.
Our Windows software (based on Stream Transcoder V3) runs as a Windows service and handles multiple sound cards, but not in a single running instance. However, this is not as bad as it sounds. All a feeder needs to do is follow a simple set of instructions (only once for each feed) to add a new feed to the service and then the Windows service handles the rest. If everything was set up correctly the setup never has to be touched again. So it is not installing software three times, it is installing a single time and then running a single command for adding each additional feed. As long as Windows "sees" the additional sound card, the LiveATC software can see it as well.
Hope this helps clear things up.