Hi Mauricio,
thanks for the comment, glad the post is helpful! 🙂
To your first question: That is to prevent inlining of things that are loaded via url() in the CSS: https://github.com/webpack-contrib/css-loader/issues/44
To your second question: not really, sorry. I did not work on really setting up a webpack config for some time now, I am using the NPM package @wordpress/scripts now that comes with a webpack config, that creates source maps for JS code.
Best,
Florian