If you were making small changes to see what worked in different browsers, rather than editing the CSS or SASS, it may be more beneficial to use the browser's Web Tool to do it live!
Yes, but only when you are making small changes to a single, and relatively static, page. And, you need to make the same changes in every browser at once. And, then you need to verify that the css changes you made correspond to the sass changes you make in the main document.