Was wondering if, for an A/C or Dehumidifier, are the evaporator coils
MORE prone to rust if the fan is NOT allowed to keep running for a period
of time after the compressor shuts off, or does that not make any
difference in terms of rust developing in the evaporator coils. Seems to
me if the fan is allowed to run for a period of time, this helps dry the
evaporator coils...would that mean they are less likely to rust or
corrode?

Even ignoring the corrosion (which shouldn't be a problem, they're
normally made to be wet), we leave our fan on all of the time. It avoids
hot/cold spots in the house, and keeps us from needing to run it quite so
much. Ceiling fans, even on low speed, help too.

steve