I fixed the issue with the window. I moved it forward so that it’s only intersecting two faces, instead of four. That’s what was causing the fuglies.
Also, here’s a good look at why I do the test renders, as opposed to just taking the 3D viewport’s word for it:
You can see some of that stuff that was visible in the render with the window farther back in the 3D viewport, but it doesn’t show up in the higher quality render.