Is it practical to transfer the Camera's video + audio Serially via RS232, then the data wirelessly via Miwi Radio, and then via I2C to a GLCD + Speaker?
I agree with the last two comments.
To transmit video you need the bandwidth of a broadcast transmitter. If you compress the video then less bandwidth. Many cameras are high resolution than broadcast so you need a faster signal. Either way you need a great deal of information in a short time. RS232 was never built for video or even just audio.
There are a number of 2.4ghz wireless cameras. They work but they seem to eat up the 2.5ghz band.