Is it a hovercraft? Is it a plane? No, it's an Ekranoplan

People in Seattle know the phrase "Skid Road", not "Skid Row". The term evolved concerning the people living south of Yesler Street in old time Seattle, the corduroy skids were placed across the trail, to enable other logs to be skidded down the hill to the saw mill using horses. If you lived south of the "Skid Road", where women of ill repute and most of the bars were, you had "Hit the Skids" and lived on "Skid Road".

But a road WOULD be tough to hoe, what with all the pavement and needing to dodge traffic all the time!

Aside from the ones that are simply correcting misspellings for words pronounced identically (sew vs sow, baited vs bated) these aren't generally true. While its true that myriad and plethora once had different connotations, those have fallen out of common use, so you aren't incorrect when you use them either way, because per common English, you are correct. Could care less is another one - its an idiomatic expression that makes use of figurative language to suggest the opposite of what it says literally. Virtually no non-native speaker would be confused by it. As for literally vs figuratively http://www.merriam-webster.com/video/0038-literally.htm (all their videos are awesome, by the way).

As for tough row to hoe (which is how I've heard it) speaking as someone who has hoed rows in a cornfield, hoeing a road would certainly be absurdly difficult, regardless of why anyone would actually want to do that (ancient greek punishment anyone?).

I'm actually reading this book now! It's definitely very interesting and very helpful.