Go to Settings » Reaction Buttons to configure the plugin settings.
You should be looking at this page:
Make sure "Show Reaction Button" is checked. Even if the plugin is activated, the buttons will not show if you do not take this action. It is checked by default, upon installation.
You may choose where you want the Buttons to appear but the default, at the bottom of the post, seems quite adequate to me.
You may also change the tagline. Use your own words, if you like.
The default Buttons read: Awesome, Interesting, Useful, Boring, and Sucks. I do not particularly like the last button title, so I simply deleted it. You may replace it with another word, if you like. Personally, I do not care to give a reader too much to focus on and 4 choices seem enough to me.
It's not a discouragement to write a comment, but it might engage the "laziness" in some people and therefore you might get less comments than you would get without the activated plugin. Only in this way, I'd be a little leery about using it.
On the other hand, if someone really wants to comment, they will and, as you say, it would be a way for folks who do not want to disclose who they are or their other demographics, it's a way to get feedback.
Getting comments is an important aspect of engagement with other people and adds to the content, which in turn, helps with ranking, not to mention building relationships with your readers..
These are my thoughts about it Tria.
Daniel