18+ months later and I think that Stylelint is probably the best path forward for those looking for a logical successor to Sass-linst.
Looking at my original list of requirements:
Supports sass and scss syntax - It supports these and more
Has a CLI that can integrate with CI workflows - It has a CLI
Has an easy JSON configuration syntax, and the tool will ...
Visual Studio Code
Visual Studio Code is a free, open source, fast, lightweight editor perfect for your basic needs, but also extensible enough that you could mostly replace Visual Studio with it if you wanted to.
A directory structure of your choosing should provide the tree organization you are looking for.
I use Ctrl+Shift+F to ...