Sure if you have the skills to do it, but it's not going to be as easy as me giving you a couple simple snips of CSS code and that's it. The templates retained the same left margin semi fluid structure as the Etano default.
There were many reasons why Etano was created as a semi fluid layout with a left margin, but one of the main reasons is because it was the most cross browser compliant solution. Every layout format has it's pros and cons, and everybody has their own opinions and arguments as to which is the best for a particular project.
The bottom line is that it's impossible to appease everyone so it was determined the best overall choice that suited the Etano project was a left margin semi fluid layout, because it was the most flexible and cross browser compliant solution as a default layout to try and appease the masses.