I deleted my reply because I got it to work. On hindsight I should have probably left it up and then explained why I got it working.
Here's what I did to get it to work.
I followed the tutorial. The part where it said to fix the graphics. You know, fullscreen, VSync on...all of that. Turns out the role of Village Idiot will be played by Antiquitas.
It was such a basic thing and I can't believe I missed the most basics of basics. I am the dumb. That was literally it. Adjust graphics to match what you had on screen. Done. Works perfectly now.
Works so well I have a bajillion mods added and it still works. Works wonderfully too. Seriously...VSync on...lower shadows...Fullscreen. How am I this dumb?