There is a massive difference between 1.9 themes and 2.0 but once you get your head round how 2.0 themes are constructed is it straight forward (there are still the odd quirks buried in there).
I would have a look at how the standard theme is constructed and copy and rename the folder and tweak the css from there. chrome is very helpful in testing css changes.
If you use something like Chrome and you're inspecting the Standard theme , you'll see different id tags and classes being used than some of the ones you've listed in your CSS snippett. For example, #content is now #page-content, #right-column is now #side-post and so on. In the theme config file for your new theme you can call the base theme and the standard theme so that you need to do is create your new CSS file and add your modifications to that. You can also add new layout files for your pages and so on but be careful, the theme engine is not consistent over its use of layout pages especially when it comes to admin and report pages. Themes - MoodleDocs is a good start. Hope that helps.
Having a bit of a nightmare here trying to create a moodle 2 theme.
Just wondering how you got on with this, any progress? I am using 1.9 on our website here and the theme I made was a pain in the rear the first time round I don't know if i'm ready for the headache of changing it to 2.0 if its more effort than its worth.