wall mount tv

Split face tiling on plasterboard, if I take some off would the plasterboard hold a tv on the wall too? It is located on the outside wall so would it be best to drill straight into the brick to be able to get the tv up?

I'm planning to mount a TV on a chimney breast and am trying to work out the best way to hide the cables (a power cable, HDMI, and possible an Ethernet cable.) What I picture in my mind is putting two holes in the chimney, one behind the TV and one at the side and connecting the two with some...