2 questions: changing content width and editing the caption field

Hi there, I've recently started using Catch Box on my website (http://emmalindhagen.com/). Awesome theme, but there are a couple of tiny things I want to ask. 1. I use the layout with content on the left and the menu on the right. Is there a way to make the content side a bit wider and the menu side a bit narrower? 2. I've noticed when you insert images and add a caption, there is a - before the caption each time. Is there a way to remove this or otherwise edit how the caption box will look? Thanks in advance for your answers!