Bob,
Our coach (335RLBS) did not come with a sub-woofer so I can't help with that. We had the RCA stereo system with just left and right speakers. When we pu the washer/dryer into the area where the television sits we replaced the RCA stereo with a Sony DVD/Surround System. I thought of putting the sub-woofer where you describe but it was too big. The sub-woofer is in the slide under the end table instead. We have done some major mods to our coach. Here are some links for the Sony DVD/Surround install and entertainment center upgrades:
http://www.geocities.com/fulltimedre...cvr_upgrd.html
As to the satellite connection. I put connectors on the outside of the coach just under the cabinet in the bathroom which allowed me to feed the wires into the entertainment area very easily. Here's a link showing the install:
http://www.geocities.com/fulltimedre...shinstall.html
Here's a link that shows the new and old floor plan which will show our mods a little more clearly.
http://www.geocities.com/fulltimedre...floorplan.html