Hi!
I cannot see the plugin search bar anywhere on the page unfortunately.
The default search width is set to 100%, meaning it inherits the maximum size of it’s parent element, and you can change that on the Theme Options -> Overall box layout panel: http://i.imgur.com/Og3RkGu.png
If the width is still not sufficient, it means that the search parent container might have a smaller width set. In this case I will gladly take a look at it to see if I can suggest a custom CSS rule to change it.
You can change the fonts on the Theme Options -> Input field layout panel: http://i.imgur.com/B6nerqg.png
