Can I remove my home page banner?

 There are three options for this:

1) Create a custom home page.  This is not ideal because the categories and products would need to be added to the home page manually rather than by checking the box to assign them to the root category.
2)  There are skins that are available that allow you to customize the height of the banner. The simplest approach might be to choose one of those and have a banner with a height of just a couple of pixels.  The banner could be transparent or colored to show a line. If you are looking at the skins through Sites > sitename > Skins, the Customize Skin window has a View Notes button at the upper-right that shows any detail for that skin and how to adjust it.
3)  Use a custom skin.