Does Redactor come with a distractions free mode?
Yes! You can use the full screen mode to hide the rest of the manager when editing content.
In your configuration set, under Toolbar, add
fullscreen to your toolbar buttons. Save, and use the button whenever you want a bit more clarify.
To limit the width of the content to make sure it's easy to read, add a Maximum Width under the Appearance section of the configuration. A value around 800 or 1024 works nicely in most cases.