As of now there aren't any shifting issues that I could detect. The derailleur shifted as nicely on the way home as it ever did. There's no hanger per se - the derailleur is bolted directly to the steel dropout.

As for the aesthetics of it, though it does look nasty and painful, the rest of the bike isn't perfectly manicured, either. A few battle scars here and there, you might say. So yeah, I guess some gray paint is in order, then! Thanks fellows!