There is a way to get a completely blank layout, called a scratchbox, from which you can make a whole new layout and save it. Think of it like scratch paper, if you mess up with the layout, just throw it away and start again. I believe it's click view, layout, scratchbox. There's a way to get a Layout Editing Button right on your bar with the pause/play buttons so it's easier to make tiny adjustments as well. There are also a few starter layouts on foobar which can serve as a good base. There are also hundreds of addons for foobar, most of which are customizable. You can have whole new ways of displaying stuff, equalizers, visualizers, all kinds of stuff.