That's pretty close...
I don't know how the LG handles the audio portion of the HDMI feed, but typically I would run optical from the cable box and from the Blu-ray player directly to the receiver. That way, you get direct audio feeds, bypassing the LG TV completely.
There is no reason to run component video from the cable box to the receiver since the video from the cable box is going directly to the TV.
The A/V receiver needs to have the video output from it connected to the TV, and you should use the component video output from the Wii to the receiver, then component video from the receiver to the TV.
I am not sure if your receiver does upconversion from composite video to component video, so I would recommend that you go ahead and run composite and component video from the receiver to the TV.
It looks pretty close the way you have it, and the lack of HDMI on the receiver stinks, but isn't the end of the world. I certainly don't have HDMI on my receiver either.
Obviously, in this setup you have any number of way to run your video to the TV, so if you wanted to, you could connect composite or component video directly out of the Wii to the TV. Don't use the factory Wii cables, but buy some cables from Monoprice, then splice the cables together with RCA couplers...
For only $0.18 each when QTY 50+ purchased - RCA Jack to Jack Adaptor - Gold Plated | RCA <--> RCA Adapters