RacketScript is work-in-progress and is not mature and stable. Several Racket features and libraries are not yet implemented (eg. number pyramid, contracts, proper tail calls, continuations). There are also quite a few missing primitive functions. That said, we encourage experimentation, user feedback, discussions, bug reports and pull requests.
If you do not wish to pollute your root NPM directory, you can set a custom global location by changing your npmrc (eg. echo "prefix = $HOME/.npm-packages" >> ~/.npmrc. Then add /prefix/path/above/bin to your PATH.