For the time being, the IP cam support is video only. Once the video support has stabilized, we will look into audio. The biggest question is whether there is a standard format, like MJPEG for video. If there is a standard audio format used by most IP cams, then we will most likely support it in the future. I will look into what it'll take to use an alternate audio source.
On the iPhone, the framerate is limited on cellular networks because Apple requires that we keep the bandwidth usage down. The framerate is throttled on the iCamWeb java applet to keep CPU usage reasonable and because the java applet always uses the full image for each camera, unlike the iPhone app, which uses thumbnail images when multiple cameras are displayed simultaneously.