[9question1]

I don't know what OP is referring to here, but from discussions like this: https://stackoverflow.com/a/4417485 It seems like circa 2010 folks were referring to JavaScript as "fast" because it was more performant in some ways than other interpreted languages like Ruby and Python and those were the only major popular options at the time that people would consider for some use cases. The event loop model of JavaScript led to some creative use cases for having a single-threaded application handle many highly parallel requests that require very little CPU usage or computation but a large amount of blocking I/O, which I think was also pitched as "fast". But I think it's always been uncontroversial that interpreted languages like JS, Ruby, and Python are all "slow" compared to compiled ones for CPU heavy use cases.

[steveklabnik]

Not just that, but Google pouring way more money and engineering effort into V8 than either the Ruby or Python teams could.