Here's an even more minimal seed project i've been working on (with sass): https://github.com/badsyntax/react-seed
I've been meaning to look into Flux as well, seems like an interesting design pattern for large applications.
https://github.com/sass/libsass/wiki/The-LibSass-Compatibili...
https://github.com/sass/libsass/milestones/3.2
http://sass-compatibility.github.io/
It's at the point where I can use node-sass and Ruby Sass interchangeably for our (very large) Sass code base at my company, but we also don't rely very heavily on the newest features. Worth a try, anyway.
If node-sass doesn't work for you though, there's also a webpack loader for Ruby Sass: https://github.com/ddelbondio/ruby-sass-loader