Is it possible to disable CSS and Javascript aggregation by role? Is it possible to disable CSS and Javascript aggregation by role?

That way during content editiong or administration stages the user is not affected and can check the CSS alright, while end users received cache values as usual. If the cache lifetimes are long enough the editing can be completed before it any changes interfere with the other users.
To do exactly what you want; using hook_css_alter &amp; hook_js_alter is how to do it. Set the preprocess key to FALSE for everything.

For an out of the box solution that is fairly close to what you want https://www.drupal.org/project/advagg/ can do it. Give that role the "bypass advanced aggregation" permission and then they can add ?advagg=-1 to the end of the URL to see the change.

Will also mention that using a dev environment when altering css/js is ideal.