Quote: I would suggest that every negative should be scanned prior to any action.
Sounds like a sensible precaution to me.
Quote: I presume that film, if in good condition, could be re-washed.
I don't see why plates should be more vulnerable than film (in the same condition) - in particular if re-washing film is considered an acceptable risk, I don't see any reason why plates shouldn't be re-washed too. After all, plates underwent the same sort of wet processing as film.