Thanks, everyone.

Summary:

1. I stopped worrying, grew a spine, and finished the job. It shifts perfectly now. (It wasn't so far out of line that it was obviously bent by visual inspection; it sounds like others have been far worse.)

2. The Wolf-tooth road-link idea isn't tenable (although there was some disagreement as to why), and it shouldn't be necessary.

3. Non-sacrificial derailleur hangers should be fine on a steel frame, and the dropout can be replaced if there is does somehow break.