[MC1600]

As we've been cleaning up our new '99 4000, one order of business was to dump the vintage TV/DVD combo and get a flat screen in there.  In doing so, I discovered all kinds of wires under there and I could use some help in figuring out what's what.  All pictures reflect the TV already unplugged and gone.  Everything listed below just disappears into the wall:

1.  A regular plug.  What's up with that?!
2.  Two coax cables (one with the connector cut).  Both have plastic clips labeling one "3" and the other "8".  
3.  A set of red and white cables and another cable with a (I think) 7 pin connector.
4.  A cluster of three wires all together that are red, white, and blue.

I'll be putting a new TV in there and would love to know what's up with all this stuff.  Appreciate any help you all can offer.  Pics of everything attached.

Thanks!