Marketo is suppose to be a user friendly tool, but I have not seen it.
We wanted to design a basic email template and we couldn't do it without a web designer. I propse that much like the email design function that you make a template design function where you can ask us how many colums we would like and how many rows then allow us to edit the spacing using a standard GUI.
Additionally, for company branding purposes it would be great to be able to fill in one of those editable sections with solid colors, based on HEX or pantone colors.
Marketo claims that it is very intuitive but needs more work to hit that point.