Since your question involves a DVDR it could either be here or in the DVD Recorders forum.
What you'll want to do is hook your antenna into your Insignia's RF input(antenna input) and your Insignia's yellow video output and L&R audio output to one of your Pioneers line inputs. Then on your Pio you'll want to select the input you've chosen. You'll do nothing with your Insignia's RF output or Pios RF input or RF output, they'll be unused.
All recording will be done from your Pioneers line input(not it's built in tuner).
If your TV doesn't have a built in digital tuner then you'll need to have both the Insignia and Pio ON in order to just watch live TV or record. You'll also lose the ability to record one channel while watching a different one, unless you buy a second converter box.
As far as your Insignia, you'll want to set it's output to 16:9 squished or it might be labeled 16:9 full screen. This way you'll get true anamorphic DVDs, which is good.
Lastly if your TV does have a digital tuner then you'll want to install a 2 way splitter from your antenna with one side going to your Insignia and the other directly to your TVs RF input. This way you could record one digital channel (from your Insignia) and watch a different channel on your TV (using it's built in tuner).
I'm not sure about your scrolling picture, I haven't seen that with my Insignia CECB. Digital usually either works or not, unlike analog which could have ghosting or rolling pictures.