I don't own your camper, but I have the Genesis 3.0
1) The single SAT input only goes to the main switcher wall plate (labeled AUX/SAT) in "most" installations, (maybe not yours depending on who made your roof antenna). See photo for the Winegard wall plate to look for.
See the attached PDF for one way to connect the SAT input to the camper's coax distribution center.
2) I do not own a SAT system (yet), but the system needs to be able to "ride" multiple dish signals (more than one LNB) on a single coax. See PDF.
Here is an article that might help. HOOKING UP MULTIPLE SATELLITE RECEIVERS
3) I LOVE my Genesis 3. However, since the dealership actually hooks up the television and not the factory (the TVs are shipped in the original shipping box), they are seldom hooked up correctly.
a) The correct output to the TV should be an HDMI cable but they cost a LOT more than the cheap 3 wire composite/stereo (Yellow, Red, White RCA plugs) one most dealerships use.
You will need to trash that and buy an HDMI cable long enough to get from the main TV HDMI input to the Gen 3 output on the back for high-definition output from the DVD player in the Gen 3.
b) Getting audio FROM the TV to the back (or front) of the Gen 3 (or any other make of sound system depends on the brand of TV shipped with your unit.
If it has stereo RCA (Red and White) audio out, you can use those outputs to run to any RCA audio input on the Gen 3.
If your TV has a digital output (required to get true surround sound from the TV to the Gen 3), you will need to buy a digital (fiber optic) cable long enough to get from the TV to the back of the Gen 3 (where the digital input is located).