Re: right bar
In the stylesheet for the theme you're using (in the styles/ directory). Something like td#leftcolumn and td#rightcolumn for themes using tables for layout, which is nearly all of them. Things are more involved for table-less themes (only simple.css so far), but also doable. If the module boxes don't expand to fill the widened columns, they may also have a width set, so check div.box, etc. in the stylesheet.
-- Gary