Native calls from C# are MUCH better than then the Java experience. It's a massive part of why I chose it when it came out. Today, C# is pretty great... not ever MS dev shop, which is often, like Java, excessively complex for its' own sake.

On #2, I generally reach for either TS/JS with Deno if I need a bit more than a shell script, or Rust for more demanding things. I like C# okay for the work stuff that I do currently though.