Can't get generated content to push footer down
First of all, never modify a core theme. Sub-theme. :) Second, the problem is that you are specifying "position:absolute" on some of your blocks which causes the CSS box-model to ignore any content inside the wrapper divs. When you write absolute, you are telling the browser: I know exactly where my content will be and so therefore you should ignore any flowing you want to do.

Try moving away from using position:absolute to position elements and instead use floats which will push the content region height and, in turn, your footer.

More info: http://www.w3schools.com/css/css_boxmodel.asp