Item 1 is likely related to the spread of the railroads and how important they were so early on. I knew about railroad cops, and the no Social Security eligibility, but it wasn't until the recent strike threats that I learned how railroad employment is so different from most other employment because there are specifically different laws. The importance of the railroads is why there is so much checkerboarded land in the western US, it was given away in grants to the railroads. https://en.wikipedia.org/wiki/Checkerboarding_(land)

The railroads using shorter trains would allow them to keep the trains in the railyards, where they have more physical control. But that would involve more employees and seems to be something the rail companies are specifically avoiding for various reasons.