Just out of curiosity, does it have to be live?
Nope. In fact, if you were to prerecord a show and set up an RSS stream for it, I could automate the entire process. That would be so much easier. As it is now, I have to be here at the computer to let somebody come on live and then to let them leave. I haven't figure out how to make that easier yet. Not that it matters since nobody will ever get around to doing their live shows.
If you wanted to switch to Liquid Soap, I could help you set up that automation. With Liquid Soap, it's incredibly simple: Just set up the master stream to break-in the various live streams when they are active, then password protect the live streams so that only the intended DJs can use them. They connect to their individual live stream on the server, activating it, which liquid soap notices and switches to (with all sorts of optional programmable transitions).
However, I'm not sure how to replace much of the other automation you currently use with liquid soap programming, as I'm pretty new to it...