You can stream video and audio from one or more IP cameras, and you can stream from shoutcast at the same time using the same application; in the StreamManager step use MediaCaster type "rtp" to start the camera, and use MediaCaster type "shoutcast" to start the shoutcast stream.
You have to use 2 .stream files. Each one will have one URL only. Start them separately with the necessary MediaCaster type.
If you are going to want them to be synchronized in anyway, there really isn't going to be a way to do that.
For VOD, you can use the Stream class to publish live streams using static content:
We do have an add audio track module and I will look at how we can integrate an add video track module. As Salvadore has pointed out there would be no way to synchronize the video with the audio, however an output stream could be created. As with the add audio track module now the video asset would need to be a local file for Wowza to use.