sigh. short version of a dozen or so very long threads....though they are interesting in various ways, it is a lot to sit through and digest.
get some corrosion x and do some spraying on a regular basis, that will stop the spread. You'll have to live with the corrosion, it's just an unfortunate fact of life. I was unable to get to a couple spots right away, they did spread further, but all the easily accessible spots have not spread further once I started spraying (once a month or so depending on weather).
some people then cover with clear finger nail polish or some kind of clear coat pen. some people first sand with very very high grain, not sure I'll bother with that route. I am considering the nail polish on a couple of the larger more progressive spots, but am basically just using the corrosion x for now.