In answer to your first question:
The image file for that part of the theme can be found at "wp-content/themes/s5_Political/images/Shape5_Political_logo.png" on your server. You can either rename it to have it disappear or replace it with a different image with the same dimensions.
The answer to your second question can be found here:
http://www.shape5.com/component/option,com_smf/Itemid,75/topic,15211.msg60160/#msg60160