Video and Audio Switcher

Can anyone spot any problems with the below project? I have limited funds and don't want to build it without knowing it will work.

The project is an AV switcher with the following features:

The device can switch between video inputs from 2 games consoles and an S-Video port from a laptop and send the video output to the RCA input of a TV.

The device can switch between audio inputs from the 2 games consoles, the TV itself and an extra input (could be connected to a phone, MP3 player, the laptop, etc.). This audio can then be sent to either a headphone socket or to an amplifier system I already have set up.

I have attached the circuit diagram. Switches with boxes around them indicate that they move in unison (ie. the second boxed switch is of the DPDT type).

PS. The image is quite small, I would suggest viewing it at 200%. I will try to upload a bigger version in a few minutes

maybe some help??block diagram of a 4066

Hope this helps.
I understand that this quad switch is used in stereo equiptment etc.

Thanks for the file, but not really what I'm looking for. I've checked the circuit I posted and I think it should work, would it still be ok to use a common ground for the audio and video signals? That way I can use the chassis the common ground and I don't need to worry about insulating the plugs from the aluminium case.

As in your previous post (why make a new one?) it's desirable to have a common ground.

The new post was to actually get comments on the plan and this time I asked about common grounds on the audio and video