By default, comments are enabled on Fargo blogs, but they are hidden (you have to click on "Show comments" to see them). If you want to selectively remove comments entirely on a particular post, or show comments on posts that are already generating a discussion, you have to add new attributes to the title headline.
To save you some time, here are some short scripts you can use. You first have to create an outline called menubar and title the top headline something like Scripts. Then paste the following below that headline, and make sure to indent them so that they are children of the Scripts headline:
A new menu bar will show up to the right of Docs. If you want to show comments or remove them, put your cursor on the title of your post, and click on the appropriate item in the menu.