Do I need both Get Recent Comment and Comment Rating Widget plugins?

No you don’t.  You only need to have Comment Rating Widget activated.  If you keep both plugin activated, there will be a conflict.

In fact, if you had Get Recent Comment installed before, you need to click the “Reset template to default” to get the Comment Rating Widget template.

Is there a way to manually add users avatars?  Is there a way to make the post title a link?

Yes, Please change the display template, see image, to

 <li> %gravatar  <a href="%comment_link" title="%post_title, %post_date">
   %comment_author:  %comment_excerpt</a>  %comment_rating</li>

How do I show just “Likes” thumb-up in the Widget and both thumbs in the comments?

You can choose to display different style of images in the comments and in the widget.  Please see image below for configuration.

I cannot see the Comment Rating images/votes on my sidebar.

Please check the Comment Rating Widget option page, the default template should look like the following.

<li><a href=”%comment_link” title=”%post_title, %post_date”>%comment_author</a>: %comment_excerpt %comment_rating</li>

If not, please  click the “Reset template to default” to get the Comment Rating Widget template.

How do I control the displayed image and rating in the widget?

The comment rating and images on display can be “Likes only”, “Dislikes only”, or Both.  This is customizable by the “Value for comment_karma” option in Comment Rating (under Advanced Option).

I made the change to the Comment Rating “Value for comment_karma”, but there’s no change on the sidebar.

The plugin comes with an internal cache to reduce performance impact on page loading.  You have to clean the cache by clicking on Comment Rating Widget option “Update recent comment options” at the bottom.

If the Comment Rating plugin is not installed, will this widget still work?

Yes, this plug in will function exactly as “Get Recent Comment”.