Are you talking about the Programming Languages course on Coursera? I intend to do it someday. The first few videos seemed very nice, indeed.

Phoenix is about webdev, but Nerve is not. There was a recent thread on HN on using Elixir for Machine Learning. Maybe look into that? Elixir is just very pretty in my eyes.

Scala is dominant in big data for almost a decade now. Haven't heard that about F#.