Right now there is the same amount of space between the left edge of the first widget and the left edge of the browser window, as there is from the right edge of the last widget and the right edge of the browser window. I added a border around each widget using a browser inspector so you can see what I mean:
https://cloudup.com/cj3fakT2jUp
To look balanced - no matter what content each widget area contains - each widget container, designated with the class widget-area, has a fixed width.
Were you the main developer behind this theme ?
I work with Automattic, the developers of Kelly. You can read more about the creation of Kelly - named after its designer Kelly Hoffman - here:
http://en.blog.wordpress.com/2014/05/29/kelly-and-arcade/
I'm also trying to figure out how to center the list of 8 items after the first paragraph on this post
Looks like you're alreading getting help on this one in another thread.