My number 1 request would be to be able to increase the screen width of a website and for it to be responsive. To be able to expand the blog feed to be wider would be great as well as other elements without them causing an error because they were moved outside of the dashed width lines.
I wish I could increase my website width by an 1.5 to 2 inch out each side. It's just so skinny and doesn't look as dynamic as WordPress sites. Would love to see this feature!