need help with writr theme

Here are some things that I would like to add to my blog. I am using the ‘writr’ theme:-

1) even after enabling wider content area, there is a gap left out on the right side, I would like a ‘right sidebar’ to fill up this gap.

2) I would like a custom header at the top (full width).

Is it possible to add these features? Thanks in advance.

here is my blog: a bolt of blue