Actually, it was about the ENB, too, at least for my problems.
If you looked at the screenshots, you'd notice that the torch on the wall was not emitting light properly. It didn't simply look weird, it was downright wrong. In fact, it looked a lot light there was an invisible point of light in front of the torch, pointing towards the wall (thus, the torch itself is casting a shadow, and the only light is against the wall). Like Neovalen described, it's almost a flashlight effect.
I don't like fiddling anymore with the gamma and brightness settings that I have -- turning up the brightness and gamma in such dark games makes things visible, but it also washes out the colors.
With the shader fix that I posted, the torch (and all other light sources in game) now emit light in a way that is more realistic. Not entirely sure what the fix does, but it does something correctly. ;) Anyhow, it may be worth looking into for users of ENB v. 119 who have issues similar to mine. I get very nice visuals now.