2) There is no Cable Out jack on the Pioneer 3510....only s-video....and I was getting a clearer signal through the Cable Out on my old SA...
I have the exact same issue so here is what I did: I ran the coax from the wall into a splitter. One coax from the splitter straight to the TV so I get a good analog picture. Then I ran the second coax to the STB and then S-Video and the component back over to the TV. The S-Video is supreme for Digital and Component well a must for the HD, but the coax is the best for the analog channels....This works find and I really did not have a pq change after introducing the splitter into the setup
Shine's answer should take care of question 1 - let us know if not. He is on the money you can set the STB in the extra settings to put out 4:3 / 16:9 picture depending on what it receives, you can also set what format it outputs - 480p,108i,720p,480i - great little box. In Charlotte they have the manual on Channel 411 (I think or right around there). It is a OnDemand function so you just go and look for the subject you need help with - pretty smooth.