Setting columnCount in Magento 1.9 RWD

Question

Is there an actual way to handle the columnCount in Magento's 1.9 RWD theme?

It is not possible to use addColumnCountLayoutDepend in layout.xml to set the column counts depending on the page layout in this theme and is only used to set the maximum columns.

I can manually set $_columnCount = 2; in the list.phtml and whilst $_columnCount; outputs 2, the columns on the front end don't actually change.

I see that the widths (%) for the <li> items are all hardcoded in styles.css to 4 decimal places - surely there is a way to handle this without altering all the widths in the stylesheet to get the amount of products per row you want in your grid?

Even if it were a case of altering all the widths, how do you get this perfect with 4 decimal places like so:-

width: 30.8642%;
margin-right: 3.7037%;

I'm sure I must be overlooking something else?