Hi! For the circle not to appear you’ll need to go to your Custom CSS Section in your Theme Options Panel and enter the following code:
#page-loading {background: transparent!important;
display: none !important;}
I’ve tried your page on a smaller screen and the header seems to be adjusting properly. What would you exactly need it to look like? You can chek in this site: http://css-tricks.com/snippets/css/media-queries-for-standard-devices/ how to adjust specific CSS only to a given screensize.
Let us know so we can continue working on the issues!
Cheers!