This closely resembles implicit conversion from C++ and in many serious codebases it is considered poor practice because it leads to a lot of hidden control flow.
I think Rust strikes a nice balance but there’s enough magic that some people still get frustrated. Following traits can get tedious at times.
Yes, for most real-world examples JavaScript is significantly slower; JIT isn’t free and can be very sensitive to small code changes, you also have to consider the garbage collector.
Speed is also not the only metric, Rust and C enable much better control over memory usage. In general, it is easier to write a memory-efficient program in Rust or C than it is in JS.
mpd is the single best music player for what you're describing. You can choose how you want to interact with it. And if you can't find an implementation you like, the API is simple enough you can write something yourself.
You might enjoy attending programming language events such as OPLSS (all of the old lectures are online and free to watch) or ICFP. You get to learn about lots of new research in programming languages, and often, you'll have an opportunity to explore programming languages from different perspectives, including logic and category theory.
Have you explored languages with dependent type systems such as Agda, Idris, Coq, or Twelf?
You could also explore languages from an academic perspective. Benjamin Pierce has written several high quality texts about topics in programming languages.
I think Rust strikes a nice balance but there’s enough magic that some people still get frustrated. Following traits can get tedious at times.