Okay, so I have been playing with this for the last couple of hours, and I made a little progress I think.
So I turned off TwinView and changed to Separate X screen and enabled Xinerama. I found as you stated that Xinerama and TwinView run pretty much the same.
So then I left it on Separate X Screen and turned off Xinerama, and now I am able to set the background and it shows up on both screens. Meaning that I have to exact copies of the background, which is perfectly fine. The problem that I have now, is since I am not using Xinerama or TwinView, I am unable to move any windows between the screens. Even if I try to start an application (DISPLAY=:0.1 chromium-browser) it always starts on screen 0.0. At least I am not getting the segmentation fault errors any more. But as it stands now my second monitor is pretty much useless other than looking at my background.
Also I realized that no matter what setting I choose when I do an echo $DISPLAY it always only says 0.0
I did find that I can use Nitrogen to set the background on a screen, but I am only able to do that through the GUI. I did not find a CLI option for Nitrogen to specify the monitor.
I didn't think this would be that complicated, but I guess I was mistaken. I think that I am close, but I don't know what to do now.
Do you have any more suggestions, or maybe a website that I could go read through?