Do not edit the Twenty Eleven theme. It is the default WordPress theme and having access to an unedited version of the theme is vital when dealing with a range of site issues. First create a child theme for your changes. Or use a custom CSS plugin.
Not entirely sure what you mean, but perhaps using “display: none;” in the CSS code for the header elements (h1, h2, etc.) would solve the problem? It hides them from view on the page, but leaves the code intact in header.php.
thanks, actually I would the text to appear overlayd with the chart. When I keep the H1/H2, they are shown on the top of the page, with the picture below it. I would like the H1/H2 text to overlay the chart, such that I can use a picture without, and custom Site Title and tagline with the wordpress GUI.
Ah, okay, well you can do that in a few ways — one is to use the image as a background (done in the CSS) or you can do overlay using z-index (if needed) and/or margin settings (negative margins may be relevant).
I’d suggest using Firebug for working with CSS and looking up CSS on this site: